Benjamin Silk, an epidemiologist at the Centers for Disease Control and Prevention (CDC), said that COVID-19 vaccination resulted in better protection against subsequent infection than surviving a previous infection before the arrival of the delta variant. However, looking at the cases from the summer and fall of 2021 when delta became the dominant strain in the U.S., he said that surviving a previous infection provided greater protection.
The CDC also noted that data from over a million cases in California and New York in 2021 showed that those who were unvaccinated and hadn't previously contracted the virus face a far greater risk than those who had been infected or had received their shots.
Further, the CDC pointed out that the timing of the research coincided with the waning of vaccine-induced immunity, which occurred before the wider rollout of booster shots. Silk added that the research did not apply to the current omicron wave.
While the omicron variant is milder compared to previous variants, it is more transmissible, and the sheer number of cases it caused put a lot of strain on hospitals in many parts of the country. While it isn't clear how the course of the symptomatic omicron infections differs in unvaccinated and vaccinated or previously infected individuals, reports suggest that the infections are milder in those with prior immunity.
Some people believe that recovery from infection should count alongside vaccination as protection against the virus to be at work or enter restaurants with vaccination requirements.
Research has shown that infection can train the immune system to guard against coronavirus in different ways. (Related: Truth hurts: 96% of omicron cases in Germany are among the fully vaccinated.)
Infection rates among the vaccinated who haven't had COVID were 6.2-fold lower than those who were unvaccinated in California, and 4.5-fold lower in New York. But here's he catch: People who previously had COVID but had not been vaccinated had 29-fold and 14.7-fold lower case rates in California and New York, respectively.
Hospitalization rates in California also followed a similar pattern. Hospitalizations in October were 19.8-fold lower for those who had been vaccinated but hadn't had COVID, 55.3-fold lower among unvaccinated people who had COVID and 57.5-fold lower among those who'd been vaccinated and had COVID.
California state epidemiologist Erica Pan said hospitalizations among those who were vaccinated mostly involved older people. Incidences of people who have been vaccinated were highest among those who received Johnson & Johnson shot, followed by Pfizer and Moderna shots.
Infection-derived protection was also found to be higher after the delta variant became the dominant strain. (Related: Omicron COVID variant found ONLY in fully vaccinated.)
The new CDC report noted that the analyzed data are from the period in which the vast majority of people have received two shots at most. It was only in mid-October that the government authorized booster shots for those who completed their initial schedules. Boosters were not given to adults until November.
Watch the video below for more information about COVID-19 vaccines.
This video is from the Thrive Time Show with Clay Clark on Brighteon.TV.
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