Search results
Feb 27, 2024 · The Vaccine study confirmed that the Moderna and Pfizer/BioNTech vaccines are linked in rare cases to myocarditis and pericarditis, conditions involving inflammation of the heart muscle and...
Sep 20, 2021 · The first results from the highly anticipated trial studying the effectiveness and safety of the Pfizer and BioNTech COVID-19 vaccine for children ages 5 to 11 showed promising results.
Nov 7, 2023 · COVID-19 vaccinations are now part of the immunization schedule for children age 6 months and older. Kids can get a COVID-19 vaccine during their well-child visit or anytime they become eligible based on the vaccination schedule.
- Overview
- Discussion
- References
On July 15, 2022, this report was posted online as an MMWR Early Release.
Altmetric:
Citations:
Views:
Views equals page views plus PDF downloads
Tables
Data from the Omicron BA.1 sublineage surge in the United States during December 2021–February 2022 determined that VE was reduced compared with that during the previous Delta-predominant period (6). To date, estimates of differences in VE between the Omicron BA.1 and subsequent BA.2/BA.2.12.1 sublineage periods have been limited. In this estimate of VE against ED/UC visits and hospitalizations during the BA.1 and BA.2/BA.2.12.1 periods, VE declined during both periods ≥150 days after the second vaccine dose, highlighting the need for a third dose (i.e., the first booster) for eligible adults. Recent receipt of a third dose increased VE; however, some decline was observed ≥120 days after receipt of the dose. Among eligible adults aged ≥50 years, a fourth vaccine dose ≥120 days after receipt of the third dose improved VE during the BA.2/BA.2.12.1 period, although follow-up time after dose 4 was limited. These findings highlight the importance of staying up to date with COVID-19 vaccination, including recommended booster doses.
Although data on neutralizing antibodies have found BA.1 and BA.2 to be similar, recent data indicate slightly more immune escape for BA.2.12.1 (1). Data reported on Omicron sublineage VE have been limited. A study in the United Kingdom found inconsistent differences in VE for symptomatic COVID-19 and COVID-19–associated hospitalization, with higher VE against symptomatic COVID-19 but larger declines in VE against hospitalization observed during a period of BA.2 predominance versus a period of BA.1 predominance starting 10–14 weeks after a third COVID-19 vaccine dose (7). A study in Qatar found that after a second or third mRNA vaccine dose, declines in VE against symptomatic COVID-19 during BA.1 and BA.2 periods were similar, but the study did not identify enough severe cases to separate VE estimates by predominant variant (8). Differences between the current study and previous studies, including differences in proportions of persons with previous SARS-CoV-2 infection and the absence of BA.2.12.1 infections outside the United States might account for some variability in findings. After the BA.1 surge in the United States, a larger proportion of adults were found to have experienced a recent SARS-CoV-2 infection during the BA.2/BA.2.12.1 period, with antibody evidence of SARS-CoV-2 infection increasing from 33.5% in December 2021 to 57.7% by February 2022 (9). Unvaccinated persons were used as a referent group in VE analyses. If unvaccinated persons were more likely to have experienced recent infection, and infection-induced immunity provides some protection against re-infection, this could result in lower VE observed during the BA.2/BA.2.12.1 period. Although adults with documented past SARS-CoV-2 infection were excluded, infections are likely to be significantly underascertained because of lack of testing or increased at-home testing (10). In addition, although time since receipt of the second or third vaccine dose was stratified by time intervals, on average the time since vaccination was longer during the BA.2/BA.2.12.1 period. These differences were particularly pronounced in the analysis of ≥150 days after the second vaccine dose (median 289 days for hospitalized adults during the BA.1 period compared to 371 days during the BA.2/BA.2.12.1 period), which could account for some differences in VE estimates and highlights the importance of a third dose (first booster) for those who have not yet received it.
The findings in this analysis are subject to at least four limitations. First, previous SARS-CoV-2 infection was likely underascertained and might differentially affect observed VE during the BA.1 and BA.2/BA.2.12.1 periods. Second, residual confounding in VE estimates is possible. Third, no genetic characterization was available for SARS-CoV-2–positive specimens; therefore, date of testing was used to ascribe likely sublineage, and BA.2 and BA.2.12.1 sublineages were combined, given their overlap in circulation. Finally, this report did not assess VE against the most severe COVID-19–associated disease (e.g., respiratory failure) because of smaller numbers of these cases.
VE should continue to be monitored in the setting of newly emerging sublineages and variants, including Omicron sublineages BA.4 and BA.5, which became predominant in the United States in late June 2022. Eligible adults should stay up to date with recommended COVID-19 vaccinations, including a first booster dose for all eligible persons and second booster dose for adults aged ≥50 years. Booster doses should be obtained immediately when persons become eligible.
1.Hachmann NP, Miller J, Collier AY, et al. Neutralization escape by SARS-CoV-2 Omicron subvariants BA.2.12.1, BA.4, and BA.5. N Engl J Med 2022;387:86–8. https://doi.org/10.1056/NEJMc2206576 PMID:35731894
2.Altarawneh HN, Chemaitelly H, Hasan MR, et al. Protection against the Omicron variant from previous SARS-CoV-2 infection. N Engl J Med 2022;386:1288–90. https://doi.org/10.1056/NEJMc2200133 PMID:35139269
3.Feikin DR, Higdon MM, Abu-Raddad LJ, et al. Duration of effectiveness of vaccines against SARS-CoV-2 infection and COVID-19 disease: results of a systematic review and meta-regression. Lancet 2022;399:924–44. https://doi.org/10.1016/S0140-6736(22)00152-0 PMID:35202601
4.Food and Drug Administration. Coronavirus (COVID-19) update: FDA authorizes second booster dose of two COVID-19 vaccines for older and immunocompromised individuals. Silver Spring, MD: US Department of Health and Human Services, Food and Drug Administration; 2022. https://www.fda.gov/news-events/press-announcements/coronavirus-covid-19-update-fda-authorizes-second-booster-dose-two-covid-19-vaccines-older-and
5.Thompson MG, Stenehjem E, Grannis S, et al. Effectiveness of Covid-19 vaccines in ambulatory and inpatient care settings. N Engl J Med 2021;385:1355–71. https://doi.org/10.1056/NEJMoa2110362 PMID:34496194
6.Thompson MG, Natarajan K, Irving SA, et al. Effectiveness of a third dose of mRNA vaccines against COVID-19–associated emergency department and urgent care encounters and hospitalizations among adults during periods of Delta and Omicron variant predominance—VISION Network, 10 States, August 2021–January 2022. MMWR Morb Mortal Wkly Rep 2022;71:139–45. https://doi.org/10.15585/mmwr.mm7104e3 PMID:35085224
Sep 20, 2021 · Topline readouts for the other two age cohorts from the trial – children 2-5 years of age and children 6 months to 2 years of age – are expected as soon as the fourth quarter of this year. Pfizer and BioNTech plan to submit data from the full Phase 3 trial for scientific peer-reviewed publication. About the Phase 1/2/3 Trial in Children.
Sep 6, 2024 · The recommended vaccine and number of 2024–2025 COVID-19 vaccine doses are based on age and vaccination history. Table 1. People who are not moderately or severely immunocompromised: Recommended COVID-19 vaccination schedule by COVID-19 vaccination history, September 6, 2024. Ages 6 months–4 years.
Nov 9, 2021 · This study describes immunization against SARS-CoV-2 infection with an mRNA vaccine in children younger than 12 years of age and documents the safety, immunogenicity, and efficacy of a...
