When the Omicron wave hit, the unvaccinated line shot vertically like a mountain range. The vaccinated but non-boosted line rolled upward like a hill.
The reinforced line swayed only slightly.
“The third shot really boosts immunity,” Russo said, adding that it may also reduce the chances of dealing with long-term Covid-19 effects – called “long Covid” – “because you’ve optimized protection.”
• Both Pfizer and Moderna are seeking federal approval to make the fourth shot available. (Pfizer for older people; Moderna, for all adults.) If these other boosters get the green light, they are worth considering because immunity diminishes over time. If you are several months out of your last shot or natural infection, your protection is likely to be lower.
“The further away you are from your last episode of immunity, whether it’s a shot or an infection, the more open you are to a breakthrough, symptomatic infection,” said Khabbaza, “but it is very unlikely that you will become seriously ill if you’ve had three of those times. “
What about people who are immunocompromised?
“I highly recommend vaccines, third shots, boosters, etc.,” said Segal, co-chair of the National Comprehensive Cancer Network’s Covid-19 Vaccine Advisory Committee. “Some protection, though not a robust response, is better than none.”