Vaccine efficacy against COVID-associated emergency department or urgent care visits was 87% two months after the booster. It fell to 66% by the fourth month. Vaccine efficacy against hospitalization was 91% in the first two months. It fell to 78% after the booster by the fourth month.
“The finding that protection conferred by mRNA vaccines waned in the months after receipt of a third vaccine dose reinforces the importance of further consideration of additional doses to sustain or improve protection,” the authors concluded.
Chief Medical Adviser to the President of the United States Anthony Fauci spoke during a recent COVID briefing. Fauci said that a fourth dose might be needed for subsets of people who had weaker immune responses. These include the elderly and the immunocompromised.
Vaccination saves lives
The World Health Organization (WHO) said in July 2021 that vaccines offer strong protection but protection takes time to build. People must take all required doses of a vaccine to build full immunity. Vaccines can take 2-3 weeks from the final vaccination to be fully effective. The WHO noted that it is important to continue all precautions during this period to protect yourself and others.