By Samantha Isobel Tumagan
Researchers from Pfizer and Kaiser Permanente discovered that the Pfizer-BioNTech COVID-19 vaccine is still at 90% efficacy in reducing hospitalization for up to six months.
The findings from the new study are consistent with previously published data from Israel and the United States Centers for Disease Control and Prevention on vaccine effectiveness over time, but the Pfizer-funded study is the first to look at how the delta variation may affect Pfizer vaccine efficacy progressively.
The vaccine is also effective against the highly contagious delta variant even without the introduction of a booster shot.
"The effectiveness of the vaccine against the delta and non-delta variants remained high during the study, suggesting that the vaccines worked well even when a variant was present," said Dr. Simone Wildes, an infectious disease specialist.
Despite this, the vaccine's effectiveness in preventing infections declined drastically over time, according to the study. It only stands at 47% efficiency at preventing infection after five months.
Vaccines may be less effective in elderly persons and those who have medical issues. Pfizer vaccine booster injections for people who fall into certain risk categories are being approved by the Food and Drug Administration and the Centers for Disease Control and Prevention. Many of which have already received their first dose of the vaccine.
The need for the authorization of a third dose or a booster shot remains unclear given that the Pfizer vaccine may or may not decline at a similar rate over time.