Covid vaccines remain effective, even with Delta Variant
Experts say that Covid-19 vaccines stay effective despite concerns that immunity might start to decrease over time.
There were some concerns about the effectiveness of Covid-19 vaccines after several new studies showed an increasing number of breakthrough cases with fully vaccinated people. However, the studies showed that fully vaccinated people have high protection against acute infection and death.
In July, the Israeli government published the Preliminary data that showed that the Pfizer vaccine seemed only 16% effective against symptomatic infection for vaccinated people with two doses in January. The vaccine seemed 79% effective against symptomatic disease for fully vaccinated people in April. This information suggests that immunity drains over time.
A part of research supported by Pfizer showed that the effectiveness of the Pfizer-BioNTech vaccine seemed most robust (at around 96.2%) between one week and two months after getting the second dose. However, it started to decline by about 6% every two months. Its effectiveness began to fall to around 85% after a second dose between four to six months.
Lessons from Israel
Israel was one of the fastest in the world that started vaccination. However, despite this fact, the number of new Covid-19 cases began to rise again sharply in July.
Later in July, the country started to offer people over 60 to get a third vaccine dose. Israel expanded its booster program very soon and made the third shots available to everyone over 30 in August.
An infectious disease specialist at Sheba Medical Center, Professor Eyal Leshem, told CNBC that the rate of critical illness remained considerably lower while cases were rising.
Leshem added that this situation proves that the vaccine is over 90% effective in preventing acute disease.
Hope for a treatment
Schreiber supervises research on a drug that might physically place itself into cell receptors and block the virus. Scientists hope that the method of blocking the virus instead of attacking it might be successful in the case of any future mutations.
