1. In this large population-based study of adults in South Korea, there was an increased risk of developing encephalitis within 28 days of COVID-19 vaccination only for those who received the AstraZeneca (ChAdOx1-S) vaccine, but no increased risk of developing meningitis post-vaccination. Evidence Rating Level: 2 (Good) Over 5.5 billion people worldwide have received at
Existing coronavirus vaccines are not as effective against newer variants of the virus. Two vaccine experts explain how new vaccines currently in development will likely offer better protection.