Covid-19 vaccines provide long-term protection, new study shows how

After the release of recently performed research, the ongoing encouragement of concerned authorities on people to take vaccine dosage can be explained. The study, which was reported in the “New England Journal of Medicine”, found that COVID-19 vaccine provides long-term immunity against the virus's severe effects. The expansion of the delta and omicron types has generated doubts regarding whether diminishing resistance or the more highly infectious variants are to blame for outbreak infections. Danyu Lin, PhD, Dennis Gillings Distinguished Professor of Biostatistics at the UNC Gillings School of Global Public Health argues that unvaccinated people should get vaccination right away. Vaccines provided nine months of protection against hospitalisation and serious infection following the first shot. The findings also highlight the significance of booster doses, particularly for older persons.

The study, which is a collaboration between the UNC-Chapel Hill and the North Carolina Department of Health and Human Services, examined data on COVID-19 vaccination history and health outcomes for 10.6 million North Carolina residents between December 2020 and September 2021.The study results were used by the Centres for Disease Control and Prevention to support the use of booster shots."This is an excellent example of the wonderful research partnership between the Gillings School and NCDHHS, who are working together to generate the evidence base needed to keep our communities safe," said Penny Gordon-Larsen, PhD, Carla Smith Chamblee Distinguished Professor of Global Nutrition and associate dean for research at UNC Gillings School of Global Public Health.

This data included outcomes from COVID-19 cases caused by the delta variant. However, data from this study were collected before the discovery of the omicron variant."By applying a novel methodology to the rich surveillance data, we were able to provide a precise and comprehensive characterization of the effectiveness over a nine-month period for the three vaccines employed in the U.S.," Lin said."Unlike previous studies, we estimated the vaccine effectiveness in reducing the current risks of COVID-19, hospitalization, and death as a function of time elapsed since the first dose," Lin continued."This information is critically important in determining the need for and the optimal timing of booster vaccination," Lin added.The study found that the effectiveness of the Pfizer and Moderna mRNA vaccines in reducing the risk of COVID-19 reached a peak of about 95 per cent two months after the first dose and then gradually declined.

At seven months, the Pfizer vaccine dropped to 67 per cent effectiveness, compared to the Moderna vaccine, which maintained 80 per cent effectiveness.Among early recipients of the two mRNA vaccines, effectiveness dropped dramatically from mid-June to mid-July, when the delta variant was surging.Effectiveness for the Johnson & Johnson adenovirus vaccine was 75 per cent at one month after injection and fell to 60 per cent after five months.All three vaccines were effective at keeping people out of the hospital due to severe COVID-19. Effectiveness of the Pfizer vaccine reached a peak of 96 per cent at two months and remained around 90 per cent at seven months; effectiveness of the Moderna vaccine reached a peak of 97 per cent at two months and remained at 94 per cent at seven months.

 The effectiveness of the Johnson & Johnson vaccine reached a peak of 86 per cent at two months and was higher than 80 per cent through six months.For all three vaccines, effectiveness against death was higher than that of hospitalization."Because the majority of the vaccines in the U.S. were administered more than seven months ago and only a small percentage of the population has received boosters, waning immunity is likely contributing to the breakthrough infections with the omicron variant," Lin said.Everyone age 5 and older are eligible for a COVID-19 vaccine. Those ages 18 and up should get a booster shot. The research was led by Lin with major contributions from Yu Gu, a doctoral student in biostatistics, and Donglin Zeng, PhD, professor of biostatistics. NCDHHS epidemiologists Bradford Wheeler, Hayley Young, Shadia Khan Sunny, and Zack Moore participated in the research. Shannon Holloway from the North Carolina State Department of Statistics also contributed. (ANI)