Two-dose Schedule Research Articles

Effectiveness of CoronaVac among healthcare workers in the setting of high SARS-CoV-2 Gamma variant transmission in Manaus, Brazil: A test-negative case-control study

BackgroundSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant, Gamma, emerged in the city of Manaus in late 2020 during a large resurgence of coronavirus disease (COVID-19), and has spread throughout Brazil. The effectiveness of vaccines in settings with widespread Gamma variant transmission has not been reported. MethodsWe performed a matched test-negative case-control study to estimate the effectiveness of an inactivated vaccine, CoronaVac, in healthcare workers (HCWs) in Manaus, where the Gamma variant accounted for 86% of genotyped SARS-CoV-2 samples at the peak of its epidemic. We performed an early analysis of effectiveness following administration of at least one vaccine dose and an analysis of effectiveness of the two-dose schedule. The primary outcome was symptomatic SARS-CoV-2 infection. FindingsFor the early at-least-one-dose and two-dose analyses the study population was, respectively, 53,176 and 53,153 HCWs residing in Manaus and aged 18 years or older, with complete information on age, residence, and vaccination status. Among 53,153 HCWs eligible for the two-dose analysis, 47,170 (89%) received at least one dose of CoronaVac and 2,656 individuals (5%) underwent RT-PCR testing from 19 January, 2021 to 13 April, 2021. Of 3,195 RT-PCR tests, 885 (28%) were positive. 393 and 418 case-control pairs were selected for the early and two-dose analyses, respectively, matched on calendar time, age, and neighbourhood. Among those who had received both vaccine doses before the RT-PCR sample collection date, the average time from second dose to sample collection date was 14 days (IQR 7-24). In the early analysis, vaccination with at least one dose was associated with a 0.50-fold reduction (adjusted vaccine effectiveness (VE), 49.6%, 95% CI 11.3 to 71.4) in the odds of symptomatic SARS-CoV-2 infection during the period 14 days or more after receiving the first dose. However, we estimated low effectiveness (adjusted VE 36.8%, 95% CI -54.9 to 74.2) of the two-dose schedule against symptomatic SARS-CoV-2 infection during the period 14 days or more after receiving the second dose. A finding that vaccinated individuals were much more likely to be infected than unvaccinated individuals in the period 0-13 days after first dose (aOR 2.11, 95% CI 1.36-3.27) suggests that unmeasured confounding led to downward bias in the vaccine effectiveness estimate. InterpretationEvidence from this test-negative study of the effectiveness of CoronaVac was mixed, and likely affected by bias in this setting. Administration of at least one vaccine dose showed effectiveness against symptomatic SARS-CoV-2 infection in the setting of epidemic Gamma variant transmission. However, the low estimated effectiveness of the two-dose schedule underscores the need to maintain non-pharmaceutical interventions while vaccination campaigns with CoronaVac are being implemented. FundingFundação Oswaldo Cruz (Fiocruz); Municipal Health Secretary of Manaus; Fundação de Vigilância em Saúde do Amazonas

Sputnik V vaccine elicits seroconversion and neutralizing capacity to SARS-CoV-2 after a single dose

SummaryMassive vaccination offers great promise for halting the global COVID-19 pandemic. However, the limited supply and uneven vaccine distribution create an urgent need to optimize vaccination strategies. We evaluate SARS-CoV-2-specific antibody responses after Sputnik V vaccination of healthcare workers in Argentina, measuring IgG anti-spike titers and neutralizing capacity after one and two doses in a cohort of naive or previously infected volunteers. By 21 days after receiving the first dose of the vaccine, 94% of naive participants develop spike-specific IgG antibodies. A single Sputnik V dose elicits higher antibody levels and virus-neutralizing capacity in previously infected individuals than in naive ones receiving the full two-dose schedule. The high seroconversion rate after a single dose in naive participants suggests a benefit of delaying administration of the second dose to increase the number of people vaccinated. The data presented provide information for guiding public health decisions in light of the current global health emergency.

Safety and immunogenicity of an inactivated SARS-CoV-2 vaccine in healthy adults aged 18 years or older: A randomized, double-blind, placebo-controlled, phase 1/2 trial.

BackgroundWe aimed to assess the safety and immunogenicity of an inactivated vaccine against COVID-19 in Chinese adults aged ≥18 years.MethodsThis is an ongoing randomized, double-blind, placebo-controlled, phase 1/2 clinical trial among healthy adults aged ≥18 years in Henan Province, China. Participants (n = 336 in 18–59 age group and n = 336 in ≥60 age group) were enrolled between April 12 and May 17 2020, and were equally randomized to receive vaccine or placebo (aluminum hydroxide adjuvant) in a three-dose schedule of 2·5, 5, or 10 µg on days 0, 28, and 56. Another 448 adults aged 18–59 years were equally allocated to four groups (a one-dose schedule of 10 µg, and two-dose schedules of 5 µg on days 0 and 14/21/28) and received vaccine or placebo (ratio 3:1 within each group). The primary outcomes were 7-day post-injection adverse reactions and neutralizing antibody titres on days 28 and 90 after the whole-course vaccination. Trial registration: www.chictr.org.cn #ChiCTR2000031809.FindingsThe 7-day adverse reactions occurred in 4·8% to 32·1% of the participants in various groups, and most adverse reactions were mild, transient, and self-limiting. Twenty participants reported 68 serious adverse events which were judged to be unrelated to the vaccine. The 90-day post-injection geometric mean titres of neutralizing antibody ranged between 87 (95% CI: 61–125) and 129 (99–169) for three-dose schedule among younger and older adults; 20 (14–27), 53 (38–75), and 44 (32–61) in 5 µg days 0 and 14/21/28 groups, respectively, and 7 (6–9) in one-dose 10 µg group. There were no detectable antibody responses in all placebo groups.InterpretationThe inactivated vaccine against COVID-19 was well tolerated and immunogenic in both younger and older adults. The two-dose schedule of 5 µg on days 0 and 21/28 and three-dose schedules on days 0, 28, and 56 could be further evaluated for long-term safety and efficacy in the phase 3 trials.

Safety and immunogenicity of two formulations of rotavirus vaccine in Vietnamese infants

Background and aimsROTAVIN-M1® (licensed, frozen vaccine) and ROTAVIN (second-generation, liquid candidate vaccine) are two rotavirus vaccine formulations developed from a live attenuated G1P8 (KH0118) strain by Center for Research and Production of Vaccines and Biologicals (POLYVAC), Vietnam. This study compared the safety and immunogenicity of these two formulations. MethodsA Phase 3, randomized, partially double-blinded, active-controlled study was conducted in healthy infants aged 60–91 days in Vietnam. Infants received two doses of ROTAVIN or ROTAVIN-M1 in a ratio of 2:1 with an interval of 8 weeks. Solicited reactions were collected for 7 days after each vaccination. Blood samples were collected pre-vaccination and 4 weeks after the second vaccination in a subset of infants. Non-inferiority criteria required that the lower bound of 95% confidence intervals (CIs) of the post-vaccination anti-rotavirus IgA GMC (Geometric Mean Concentration) ratio of ROTAVIN/ROTAVIN-M1 should be >0.5. A co-primary objective was to compare the safety of the two vaccines in terms of solicited reactions. ResultsA total of 825 infants were enrolled. The post-vaccination GMC was 48.25 (95% CI: 40.59, 57.37) in the ROTAVIN group and 35.04 (95% CI: 27.34, 44.91) in the ROTAVIN-M1 group with an IgA GMC ratio of 1.38 (95% CI: 1.02, 1.86) thus meeting the pre-set criteria for non-inferiority. A total of 605 solicited reactions were reported in 297 (36.0%) participants with 35.4% in the ROTAVIN group and 37.2% in the ROTAVIN-M1 group. There were no cases of intussusception or death reported in the study. ConclusionsBased on the data generated, it can be concluded that ROTAVIN is immunologically non-inferior and has similar safety profile to ROTAVIN-M1 when administered to infants in a two-dose schedule. Therefore, it can be considered as a more suitable option for programmatic use to prevent rotavirus diarrhoea in Vietnam and the Mekong region. Trial registration numberClinicalTrials.gov identifier: NCT03703336, October 11, 2018.

Immunogenicity of alternative ten-valent pneumococcal conjugate vaccine schedules in infants in Ho Chi Minh City, Vietnam: results from a single-blind, parallel-group, open-label, randomised, controlled trial

SummaryBackgroundData are scarce from low-income and middle-income countries (LMICs) to support the choice of vaccination schedule for the introduction of pneumococcal conjugate vaccines (PCV). We aimed to compare the immunogenicity of four different infant PCV10 schedules in infants in Vietnam.MethodsIn this single-blind, parallel-group, open-label, randomised controlled trial, infants aged 2 months were recruited by community health staff in districts 4 and 7 of Ho Chi Minh City, Vietnam. Eligible infants had no clinically significant maternal or prenatal history and were born at or after 36 weeks' gestation. Participants were randomly assigned (3:3:5:4:5:4) using block randomisation, stratified by district, to one of six PCV10 or PCV13 vaccination schedules. Here we report results for four groups: group A, who were given PCV10 at ages 2, 3, 4, and 9 months (a 3 + 1 schedule); group B, who were vaccinated at ages 2, 3, and 4 months (3 + 0 schedule); group C, who were vaccinated at ages 2, 4, and 9·5 months (2 + 1 schedule); and group D, who were vaccinated at ages 2 and 6 months (two-dose schedule). Laboratory-based assessors were masked to group allocation. Blood samples were collected at different prespecified timepoints between ages 3–18 months depending on group allocation, within 27–43 days after vaccination, and these were analysed for serotype-specific IgG and opsonophagocytic responses. Participants were followed-up until age 24 months. The primary outcome was the proportion of infants with serotype-specific IgG levels of 0·35 μg/mL or higher at age 5 months, analysed as a non-inferiority comparison (10% margin) of the two-dose and three-dose primary series (group C vs groups A and B combined). We also compared responses 4 weeks after two doses administered at either ages 2 and 4 months (group C) or at ages 2 and 6 months (group D). The primary endpoint was analysed in the per-protocol population. Reactogenicity has been reported previously. This study is registered with ClinicalTrials.gov, NCT01953510, and is now closed to accrual.FindingsBetween Sept 30, 2013, and Jan 9, 2015, 1201 infants were enrolled and randomly assigned to group A (n=152), group B (n=149), group C (n=250), group D (n=202), or groups E (n=251) and F (n=197). In groups A–D, 388 (52%) of 753 participants were female and 365 (48%) were male. 286 (95%) participants in groups A and B combined (three-dose primary series) and 237 (95%) in group C (two-dose primary series) completed the primary vaccination series and had blood samples taken within the specified time window at age 5 months (per-protocol population). At this timepoint, a two-dose primary series was non-inferior to a three-dose primary series for eight of ten vaccine serotypes; exceptions were 6B (84·6% [95% CI 79·9–88·6] of infants had protective IgG concentrations after three doses [groups A and B combined] vs 76·8% [70·9–82·0] of infants after two doses [group C]; risk difference 7·8% [90% CI 2·1–13·6]) and 23F (90·6% [95% CI 86·6–93·7] vs 77·6% [71·8–82·2]; 12·9% [90% CI 7·7–18·3]). Two doses at ages 2 and 6 months produced higher antibody levels than two doses at ages 2 and 4 months for all serotypes except 5 and 7F.InterpretationA two-dose primary vaccination series was non-inferior to a three-dose primary vaccination series while two doses given with a wider interval between doses increased immunogenicity. The use of a two-dose primary vaccination schedule using a wider interval could be considered in LMIC settings to extend protection in the second year of life.FundingAustralian National Health and Medical Research Council, and The Bill & Melinda Gates Foundation.

COVID-19 vaccine impact in Israel and a way out of the pandemic

In December, 2020, Israel initiated a national campaign to vaccinate its population with Pfizer–BioNTech's mRNA COVID-19 vaccine BNT162b2 (tozinameran). Israel's Ministry of Health recommended a two-dose schedule with a 21-day interval between doses. Israel delivered more than 10 million doses within 4 months; by April 19, 2021, 54% of the entire population of 9·1 million people, and 88% of people aged 50 years or older, had received two doses.1 Factors contributing to Israel's rapid roll-out include its small geographical and population sizes; advanced information technology that allowed prioritisation, allocation, and documentation of vaccines for eligible individuals; effective cooperation between government and community-based health funds, which were charged with providing vaccines to those they insured; and experience in rapid large-scale emergency responses.

Immunogenicity of two-dose and three-dose vaccination schedules with Sabin inactivated poliovirus vaccine in China: An open-label, randomized, controlled trial

BackgroundWe assessed immunogenicity of three-dose and two-dose immunization schedules with a Sabin-strain inactivated poliovirus vaccine (sIPV) produced by one Chinese vaccine manufacturer. MethodsThis was an open label, randomized, controlled trial conducted in 16 vaccination clinics in Shandong province. Infants were allocated randomly to either a 3-dose study arm (sIPV administered at 2, 3, and 4 months of age) or a 2-dose arm (sIPV administered at 4 and 8–11 months of age). Poliovirus neutralizing antibodies were measured in sera collected prior to the first sIPV dose and one month after the last dose. FindingsWe enrolled 560 infants; 536 (95.7%) completed the study. Final seropositivity rates were >98% for all three serotypes in both study arms. There were no statistically significant differences in seropositivity between the 2-dose and the 3-dose schedule. Final median reciprocal titres of polio antibodies were high overall (>1:768 for all serotypes) and statistically significantly higher in 2-dose recipients compared with 3-dose recipients (p < 0.001). InterpretationThis study offers evidence that two doses of sIPV administered at 4 and 8–11 months of age and three doses of sIPV administered at 2, 3, and 4 months of age both provide serological protection against poliomyelitis. Median reciprocal titres of polio antibodies were high overall, and were more related to the interval between doses than the number of doses, with the longer interval of the 2-dose schedule producing higher reciprocal titres than the shorter-interval 3-dose schedule. The protection provided by the 3-dose schedule is achieved earlier in life than the protection with the 2-dose schedule. Countries planning to use an IPV-only schedule in the post-eradication era can consider this 2-dose sIPV option as an immunogenic and dose-sparing strategy. FundingWorld Health Organization (from a grant from International PolioPlus Committee, Rotary International, Evanston, IL, USA).

SARS‑CoV-2 RBD219-N1C1: A yeast-expressed SARS-CoV-2 recombinant receptor-binding domain candidate vaccine stimulates virus neutralizing antibodies and T-cell immunity in mice

ABSTRACT There is an urgent need for an accessible and low-cost COVID-19 vaccine suitable for low- and middle-income countries. Here, we report on the development of a SARS-CoV-2 receptor-binding domain (RBD) protein, expressed at high levels in yeast (Pichia pastoris), as a suitable vaccine candidate against COVID-19. After introducing two modifications into the wild-type RBD gene to reduce yeast-derived hyperglycosylation and improve stability during protein expression, we show that the recombinant protein, RBD219-N1C1, is equivalent to the wild-type RBD recombinant protein (RBD219-WT) in an in vitro ACE-2 binding assay. Immunogenicity studies of RBD219-N1C1 and RBD219-WT proteins formulated with Alhydrogel® were conducted in mice, and, after two doses, both the RBD219-WT and RBD219-N1C1 vaccines induced high levels of binding IgG antibodies. Using a SARS-CoV-2 pseudovirus, we further showed that sera obtained after a two-dose immunization schedule of the vaccines were sufficient to elicit strong neutralizing antibody titers in the 1:1,000 to 1:10,000 range, for both antigens tested. The vaccines induced IFN-γ IL-6, and IL-10 secretion, among other cytokines. Overall, these data suggest that the RBD219-N1C1 recombinant protein, produced in yeast, is suitable for further evaluation as a human COVID-19 vaccine, in particular, in an Alhydrogel® containing formulation and possibly in combination with other immunostimulants.

Immunisation Coverage Annual Report 2018

Australian Immunisation Register data have been analysed for children aged &lt; 5 years, focusing on changes in coverage at key milestone ages (12, 24 and 60 months) between 2017 and 2018, while also documenting longer term trends. Fully vaccinated coverage increased at the 12- and 60-months milestones to 93.9% and 94.0%, respectively, but, in the context of additional antigens required, decreased to 90.1% at 24 months. Following the move to a two-dose rotavirus vaccine schedule across Australia from mid-2017, rotavirus vaccine coverage increased from 86.8% to 90.9%. In 2018, most jurisdictions funded influenza vaccine for non-Indigenous children aged 6 months to &lt; 5 years; the National Immunisation Program has funded influenza vaccine for Aboriginal and Torres Strait Islander children and medically at-risk children since 2015 and 2010, respectively. Recorded influenza vaccine coverage in Aboriginal and Torres Strait Islander children doubled from 14.9% to 31.4%, and increased fivefold in non-Indigenous children from 5.0% to 25.9% in 2018. The timeliness of fully vaccinated coverage was also examined at earlier milestones (3 months after due date of last scheduled vaccine) of 9, 15, 21 and 51 months, by area of residence. For all children, coverage among those living in the least advantaged residential area quintile was 3–4% lower than that for those in the most advantaged quintile at the 9-, 15- and 21-month milestones. Importantly, although Aboriginal and Torres Strait Islander children had lower coverage for the second dose of measles-mumps-rubella vaccine at 24 months (91.8% versus 93.1% for non-Indigenous), coverage increased to 98.5% at 60 months; coverage was also high in non-Indigenous children at 96.2%, above the 95% target critical to measles control. These data demonstrate continuing improvements in immunisation coverage and suggest potential new coverage targets for earlier protection in the first two years of life.

Immunisation Coverage Annual Report 2018.

Australian Immunisation Register data have been analysed for children aged < 5 years, focusing on changes in coverage at key milestone ages (12, 24 and 60 months) between 2017 and 2018, while also documenting longer term trends. Fully vaccinated coverage increased at the 12- and 60-months milestones to 93.9% and 94.0%, respectively, but, in the context of additional antigens required, decreased to 90.1% at 24 months. Following the move to a two-dose rotavirus vaccine schedule across Australia from mid-2017, rotavirus vaccine coverage increased from 86.8% to 90.9%. In 2018, most jurisdictions funded influenza vaccine for non-Indigenous children aged 6 months to < 5 years; the National Immunisation Program has funded influenza vaccine for Aboriginal and Torres Strait Islander children and medically at-risk children since 2015 and 2010, respectively. Recorded influenza vaccine coverage in Aboriginal and Torres Strait Islander children doubled from 14.9% to 31.4%, and increased fivefold in non-Indigenous children from 5.0% to 25.9% in 2018. The timeliness of fully vaccinated coverage was also examined at earlier milestones (3 months after due date of last scheduled vaccine) of 9, 15, 21 and 51 months, by area of residence. For all children, coverage among those living in the least advantaged residential area quintile was 3-4% lower than that for those in the most advantaged quintile at the 9-, 15- and 21-month milestones. Importantly, although Aboriginal and Torres Strait Islander children had lower coverage for the second dose of measles-mumps-rubella vaccine at 24 months (91.8% versus 93.1% for non-Indigenous), coverage increased to 98.5% at 60 months; coverage was also high in non-Indigenous children at 96.2%, above the 95% target critical to measles control. These data demonstrate continuing improvements in immunisation coverage and suggest potential new coverage targets for earlier protection in the first two years of life.

Safety and immunogenicity of a recombinant tandem-repeat dimeric RBD-based protein subunit vaccine (ZF2001) against COVID-19 in adults: two randomised, double-blind, placebo-controlled, phase 1 and 2 trials

Safety and immunogenicity of a recombinant tandem-repeat dimeric RBD-based protein subunit vaccine (ZF2001) against COVID-19 in adults: two randomised, double-blind, placebo-controlled, phase 1 and 2 trials

Covid-19 Pandemic and Vaccine Prospect: Lessons Learnt from HIV/AIDS

Recent media reported in India those weeks after first vaccine dose during the trial, a Minister got Covid-19. It may have hogged the headline in regard to India’s Covaxin produced by Bharat Biotech. But, the company soon issued a statement defending itself on this count stating, “Covaxin clinical trials are based on a two-dose schedule, given 28 days apart, and the vaccine has been designed to be efficacious when subjects receive both doses.”

Evolution of Public Health Human Papillomavirus Immunization Programs in Canada.

Background: Since 2007, all Canadian provinces and territories have had a publicly funded program for vaccination against human papillomavirus (HPV) infection. The objective of this study was to describe the evolution of these vaccination programs. Methods: This was a targeted literature review of public HPV vaccination programs and vaccination coverage rates, based on information provided by jurisdictional public health authorities. Results: HPV vaccination of schoolgirls began in school years 2007/08 to 2010/11 with three doses of the quadrivalent HPV vaccine in all provinces except Quebec, which started with two doses. By 2018/19, all jurisdictions were vaccinating with two doses of the nonavalent vaccine in both girls and boys, except Quebec, which used a mixed vaccination schedule with one dose of the nonavalent and one dose of the bivalent vaccines. Public HPV vaccination programs in most provinces include after-school catch-up vaccination. Immunocompromised or other high-risk individuals are eligible for the HPV public vaccination program in most provinces, but policies vary by jurisdiction. In 2017/18, vaccination coverage rates in provincial HPV school-based programs varied from 62% in Ontario to 86% in Prince Edward Island in girls and from 58% in Ontario to 86% in Prince Edward Island in boys. Conclusions: Since their introduction, Canadian school-based HPV public vaccination programs have evolved from a three-dose to a two-dose schedule, from a quadrivalent to a nonavalent vaccine, and from a girls-only to a gender-neutral policy. Vaccination coverage rates have varied markedly and only Prince Edward Island and Newfoundland/Labrador have maintained rates exceeding 80%.

Who should be prioritized for COVID-19 vaccination in China? A descriptive study

BackgroundAll countries are facing decisions about which population groups to prioritize for access to COVID-19 vaccination after the first vaccine products have been licensed, at which time supply shortages are inevitable. Our objective is to define the key target populations, their size, and priority for a COVID-19 vaccination program in the context of China.MethodsOn the basis of utilitarian and egalitarian principles, we define and estimate the size of tiered target population groups for a phased introduction of COVID-19 vaccination, considering evolving goals as vaccine supplies increase, detailed information on the risk of illness and transmission, and past experience with vaccination during the 2009 influenza pandemic. Using publicly available data, we estimated the size of target population groups, and the number of days needed to vaccinate 70% of the target population. Sensitivity analyses considered higher vaccine coverages and scaled up vaccine delivery relative to the 2009 pandemic.ResultsEssential workers, including staff in the healthcare, law enforcement, security, nursing homes, social welfare institutes, community services, energy, food and transportation sectors, and overseas workers/students (49.7 million) could be prioritized for vaccination to maintain essential services in the early phase of a vaccination program. Subsequently, older adults, individuals with underlying health conditions and pregnant women (563.6 million) could be targeted for vaccination to reduce the number of individuals with severe COVID-19 outcomes, including hospitalizations, critical care admissions, and deaths. In later stages, the vaccination program could be further extended to target adults without underlying health conditions and children (784.8 million), in order to reduce symptomatic infections and/or to stop virus transmission. Given 10 million doses administered per day, and a two-dose vaccination schedule, it would take 1 week to vaccinate essential workers but likely up to 7 months to vaccinate 70% of the overall population.ConclusionsThe proposed framework is general but could assist Chinese policy-makers in the design of a vaccination program. Additionally, this exercise could be generalized to inform other national and regional strategies for use of COVID-19 vaccines, especially in low- and middle-income countries.

Loss of protective immunity of two-dose mumps-containing vaccine over time: concerns with the new strategy of the mumps immunization program in China

ABSTRACT Background: Currently, children aged 6–9 years have the highest incidence rate of mumps in China. Although China has introduced a two-dose schedule of measles-mumps-rubella vaccine into routine immunization (at 8 months and 18 months), the incidence rate of mumps in high-risk populations might not decrease due to waning immunity. Here we report a mumps outbreak supporting this hypothesis. Methods: The descriptive epidemiological method was used to summarize the overall characteristics of the course of the outbreak. We conducted a retrospective cohort study to evaluate the vaccine effectiveness (VE) of mumps-containing vaccine (MuCV). Results: A total of 78 cases were identified during the outbreak and the estimated vaccination coverage was 84.7%. Of 454 vaccinated students, 335 (73.8%) had received one-dose MuCV, 93 (20.5%) two-dose, and 26 (5.7%) three-dose. The VEs for both the one-dose (−17.0%, 95%CI: −120.3–38.2%) and two-dose groups (−10.0%, 95%CI: −138.0–48.8%) were not performed well, whereas the VE for the three-dose group was 100%. However, we found that the overall VE was 74.2% (95% CI: 9.7–92.6%) for students vaccinated within 5 years. We also observed that there was a broadly linear increase in mumps infection risk in both one-dose and two-dose group when the time since last dose vaccination was more than 5 years. Conclusions: The overall VE for both one-dose and two-dose MuCV was discouraging, but it appeared to be moderately effective within 5 years after vaccination. Further surveillance and seroepidemiological data are needed to understand the impact of the new vaccination strategy on mumps in China.

Interim Results of a Phase 1–2a Trial of Ad26.COV2.S Covid-19 Vaccine

BackgroundEfficacious vaccines are urgently needed to contain the ongoing coronavirus disease 2019 (Covid-19) pandemic of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). A candidate vaccine, Ad26.COV2.S, is a recombinant, replication-incompetent adenovirus serotype 26 (Ad26) vector encoding a full-length and stabilized SARS-CoV-2 spike protein.MethodsIn this multicenter, placebo-controlled, phase 1–2a trial, we randomly assigned healthy adults between the ages of 18 and 55 years (cohort 1) and those 65 years of age or older (cohort 3) to receive the Ad26.COV2.S vaccine at a dose of 5×1010 viral particles (low dose) or 1×1011 viral particles (high dose) per milliliter or placebo in a single-dose or two-dose schedule. Longer-term data comparing a single-dose regimen with a two-dose regimen are being collected in cohort 2; those results are not reported here. The primary end points were the safety and reactogenicity of each dose schedule.ResultsAfter the administration of the first vaccine dose in 805 participants in cohorts 1 and 3 and after the second dose in cohort 1, the most frequent solicited adverse events were fatigue, headache, myalgia, and injection-site pain. The most frequent systemic adverse event was fever. Systemic adverse events were less common in cohort 3 than in cohort 1 and in those who received the low vaccine dose than in those who received the high dose. Reactogenicity was lower after the second dose. Neutralizing-antibody titers against wild-type virus were detected in 90% or more of all participants on day 29 after the first vaccine dose (geometric mean titer [GMT], 212 to 354), regardless of vaccine dose or age group, and reached 96% by day 57 with a further increase in titers (GMT, 288 to 488) in cohort 1a. Titers remained stable until at least day 71. A second dose provided an increase in the titer by a factor of 2.6 to 2.9 (GMT, 827 to 1266). Spike-binding antibody responses were similar to neutralizing-antibody responses. On day 15, CD4+ T-cell responses were detected in 76 to 83% of the participants in cohort 1 and in 60 to 67% of those in cohort 3, with a clear skewing toward type 1 helper T cells. CD8+ T-cell responses were robust overall but lower in cohort 3.ConclusionsThe safety and immunogenicity profiles of Ad26.COV2.S support further development of this vaccine candidate. (Funded by Johnson & Johnson and the Biomedical Advanced Research and Development Authority of the Department of Health and Human Services; COV1001 ClinicalTrials.gov number, NCT04436276.)

Continued HPV vaccination in the face of unexpected challenges: A commentary on the rationale for an extended interval two-dose schedule

Continued HPV vaccination in the face of unexpected challenges: A commentary on the rationale for an extended interval two-dose schedule

Continued HPV vaccination in the face of unexpected challenges: A commentary on the rationale for an extended interval two-dose schedule

Continued HPV vaccination in the face of unexpected challenges: A commentary on the rationale for an extended interval two-dose schedule

Immunisation schedule of the Pediatric Spanish Association: 2021 recommendations

The CAV-AEP annually publishes the immunisation schedule considered optimal for all children and adolescent resident in Spain, taking into account the available evidence. The 2+1 schedule is recommended (2, 4, and 11 months) with hexavalent vaccines (DTPa-VPI-Hib-HB) and with 13-valent pneumococcal conjugate.A 6-year booster is recommended, preferably with DTPa (if available), with a dose of polio for those who received 2+1 schemes, as well as vaccination with Tdpa in adolescents and in each pregnancy, preferably between 27 and 32 weeks. Rotavirus vaccine should be systematic for all infants. Meningococcal B vaccine, with a 2+1 schedule, should be included in routine calendar. In addition to the inclusion of the conjugated tetravalent meningococcal vaccine (MenACWY) at 12 years of age with catch up to 18 years, inclusive, the CAV recommends this vaccine to be also included at 12 months of age, replacing MenC. Likewise, it is recommended in those over 6 weeks of age with risk factors or who travel to countries with a high incidence of these serogroups. Two-dose schedules for triple viral (12 months and 3-4 years) and varicella (15 months and 3-4 years) will be used. The second dose could be applied as a tetraviral vaccine. Universal systematic vaccination against HPV is recommended, regardless of gender, preferably at 12 years, and greater effort should be made to improve coverage. The 9 genotype extends coverage for both genders.

Safety and immunogenicity of ChAdOx1 nCoV-19 vaccine administered in a prime-boost regimen in young and old adults (COV002): a single-blind, randomised, controlled, phase 2/3 trial

Safety and immunogenicity of ChAdOx1 nCoV-19 vaccine administered in a prime-boost regimen in young and old adults (COV002): a single-blind, randomised, controlled, phase 2/3 trial