Unvaccinated people who have caught and recovered from Covid-19 have better protection against the delta variant than those who have been double-jabbed but never caught the virus, according to data from the US government.
However, exposure to the virus as well as vaccination was found to give the best protection.
The Centre for Disease Control (CDC) published data on Wednesday comparing protection against infection by immunity status.
It found that during the time when delta was dominant in the US, case rates in California among those who were vaccinated but had never caught Covid-19 were 6.2-fold lower than people who had no protection from either vaccines or infection. The comparative figure for New York was 4.5-fold lower than the unprotected baseline.
However, the CDC says that cases were 29-fold and 14.7-fold lower in California and New York, respectively, for those who were unvaccinated but had previously tested positive.
The risk of catching the coronavirus was squashed even further if a person had both forms of protection – prior infection as well as vaccines – with case rates plummeting 32.5-fold in California and 19.8-fold in New York.
Experts at the CDC were keen to emphasise that a person who is unvaccinated would gain added protection from vaccination even if they previously had the virus.
The vaccine is also much safer than taking one’s chances with the coronavirus itself. For example, while the CDC was gathering data in the two US states from May 2021 through to November 2021, more than 130,000 residents of California and New York had died from Covid-19.
“The evidence in this report does not change our vaccination recommendations,” Dr Ben Silk of the CDC and one of the study’s authors told a media briefing.
“We know that vaccination is still the safest way to protect yourself against Covid-19.”
Virus wanes in previously infected people
Recent research from the UK Health Security Agency (UKHSA) found that protection from Covid-19 wanes in previously infected people who have not been vaccinated.
But, people who had been infected more than a year ago and who had also had their vaccines maintain more than 90 per cent protection against the virus.
The CDC study does not account for omicron, and does not take into consideration booster jabs.
UKHSA data show that getting a booster vaccine provides substantial protection against the new variant.
“Viruses are constantly changing, including the virus that causes Covid-19,” the CDC said in a statement.
“These changes occur over time and can lead to the emergence of new variants that have new characteristics, including ones that impact the level of immunity vaccination and/or prior infection can provide.”
The Telegraph
