The WHO defines hybrid immunity as protection in people who’ve received at least two doses of a Covid vaccine and have been infected with the virus either before or after vaccination. According to Lancet, the hybrid immunity, coupled with primary vaccine doses, was effective in preventing severe disease and hospital admission in 97.4% of participants upto 12 months. The effectiveness of only hybrid immunity against re-infection stood at 41.8 per cent at 12 months. And, the effectiveness of only previous infection against severe disease and hospital admission was 74.6 per cent at 12 months. After 12 months, protection against re-infection for all forms of immunity dipped to 24.7 per cent. It states that hybrid immunity with more vaccine doses provides more protection.