Blue Shield of California
COVID-19 Resource Center for Employers, Plan Sponsors, Brokers and Consultants

B2B General

April 22, 2021 - 4 min read

What happens after someone receives the COVID-19 vaccine?

The COVID-19 vaccines are reducing the spread of the virus, but the pandemic is not over yet. Prevention is still necessary for avoiding infection


The recent expansion in vaccine eligibility to include all individuals 16 and older has brought a flurry of excitement, especially with summer fast approaching. With more and more individuals getting vaccinated, many people are ready to let their guard down in what has felt like a never-ending pandemic.

Despite the increase in overall vaccination rates in recent months, there is still some time before herd immunity is achieved. Further, experts continue to speculate how long an individual’s immunity will last. Dr. James Cruz, senior medical director of Blue Shield of California Promise Health Plan, advises, “Even if you have already been vaccinated, we all need to remain cautious and continue with prevention measures until many more people are vaccinated. We’re all in this together, and to keep everyone safe, please continue to follow public health guidelines about wearing masks and social distancing.”

How long do the COVID-19 vaccines provide immunity?

Data from ongoing clinical studies have shown that the COVID-19 vaccines are highly effective in protecting individuals for at least six months. Research suggests that immunity after the six-month mark will not drop to zero, but will taper off as antibodies wane over time. It is also thought that immunity may even last as long as a year.  

Similar to the flu vaccine, the COVID-19 vaccines may require booster shots annually to provide continuous immunity. Pfizer’s CEO, Albert Bourla, recently shared that a third booster shot may be needed anywhere between 6—12 months after the second dose. Moderna recently shared that it hopes to have a booster available in the fall.  Ultimately the decision on whether a booster is recommended depends on public health officials, not vaccine manufacturers. Those who have already received the vaccine should hold onto their vaccination card a little longer.

While all COVID-19 vaccines are highly effective in preventing serious infection, hospitalization, and death, “breakthrough infection” is possible but rare. The CDC has acknowledged that this is the case with any vaccine and they are monitoring such cases and investigating any concerning patterns. 

Continue with preventive measures to ensure safety and avoid infection

As vaccines distribution continues to expand, it is crucial to still follow basic preventive measures as recommended by the CDC and by Blue Shield’s very own Dr. James Cruz:

  • Wear a mask (double masking may provide additional protection)

  • Maintain 6 feet of distance from others

  • Avoid large gatherings

  • Monitor symptoms of COVID-19 and stay home when illness is suspected

  • Wash hands frequently and use hand sanitizer when washing hands is not possible

The end of the COVID-19 pandemic is in sight, but it is important to remain cautious until more data on immunity become available and herd immunity is reached.

We encourage members to get vaccinated and follow safety protocols. Employers, brokers, and members can stay up to date with the latest health news from Blue Shield by visiting our News Center or by subscribing for updates.

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