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Building Toward Herd Immunity

Deborah R. Roy, M.P.H., R.N., CSP, COHN-S, CIT, FASSP, FAAOHN, 2020-2021 ASSP President
Mar 01, 2021
ASSP President Deb Roy

None of us will ever forget the year that was 2020. It created innumerable professional and personal obstacles, while also challenging us to consider new ideas and perspectives. As we move into 2021, ASSP is continuing to adapt to a shifting business landscape and I want to share an update on the state of the Society.

As OSH professionals, we have answered the call to help our organizations implement measures to protect workers throughout the COVID-19 pandemic. By working to implement public health controls such as face masks, physical distancing, and improved ventilation and hygiene, and supporting telework for those who can, we have helped to keep essential workplaces operating. 

Sadly, the death toll and long-term health impact of the virus continues to ravage much of the world. Vaccines are rolling out slowly, with two mRNA vaccine options available at press time in the U.S., both of which require two doses over 3 to 4 weeks. Two other vaccine options are expected soon, including one single-shot option. Demand for vaccine remains much greater than the supply, and a lack of coordinated response has hampered the speed of vaccination even for those in the first tiers such as healthcare workers, and those at highest risk of disease, the elderly and those with high-risk medical conditions. 

As we look ahead to when the pandemic may be over, we must consider several variables. Both mRNA vaccines are reported to be 94% to 95% effective at preventing disease, but we do not yet know whether these vaccines will protect a vaccinated individual from becoming asymptomatic with COVID-19 and transmitting the virus to others. These data should be available soon. To track the latest research, I encourage you to subscribe to CDC’s weekly COVID science updates at

A more concerning finding is that the vaccines already available and those in the near-term pipeline are likely to be less effective as variants of the virus spread. Thus far, the vaccines still largely reduce or eliminate the possibility of severe disease and hospitalization, which would help alleviate stress on the U.S. healthcare system and allow the death rate to begin declining.  

We also have to recognize the impact of pandemic fatigue, especially since we do not yet know if those vaccinated can transmit the disease. Measures such as face masks, physical distancing and avoiding large crowds will remain critical for the foreseeable future. If these proven controls wane before herd immunity is achieved, more people will be impacted by COVID-19. And we still do not know how long immunity lasts, either after the disease or from vaccination. 

With respect to herd immunity, also known as herd prevention, public health experts anticipate it will likely occur in steps over time. For example, as close personal connections are vaccinated, we can start to spend time in each other’s homes. Next, our local communities may start to report significant declines in hospitalizations and deaths, then record zero new cases of COVID-19. Eventually, cases will decline significantly across much of the country so that those who are not vaccinated are less likely to come in contact with someone who has the virus. Finally, globally COVID-19 cases will start to subside in 2022. 

It is likely that COVID-19 will remain endemic, with local outbreaks occurring periodically, particularly in areas with low levels of vaccination (as we have seen with whooping cough in the U.S.). If the SARS CoV-2 virus causes seasonal outbreaks in the future, we may need annual vaccines, much like happens for influenza. 

Based on the science and what we know as I write this message, I believe we will be able to begin socializing more locally during the summer (Q3 2021) with continued controls such as testing, masks and distancing, then move to herd immunity in the U.S. in the fall (Q4). Please visit our COVID-19 Resources web page ( to access a recently recorded free webinar during which we discuss the vaccines, herd immunity, new return-to-work strategies and preparing your organization for recurring local outbreaks. 

Please keep demonstrating the resilience that has become our trademark during the pandemic. And please continue to find effective ways to adapt as we move toward the end of the COVID-19 pandemic and beyond. 


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