COVID-19 - Dr. Jim Halverson

Ask Dr. Halverson: Israeli studies indicate that Pfizer COVID-19 vaccine reduces asymptomatic cases

web 4 17 Halverson photo
By Dr. Jim Halverson
Another significant benefit of being vaccinated against the SARS-CoV-2 virus, which causes COVID-19, was shown by two Israeli studies this past week.
Asymptomatic cases were found to be substantially reduced among vaccinated individuals in the first 28 days following vaccination. If further studies verify this result, and show that it persists, not only is the vaccinated individual protected, the vaccine also provides protection to the people in his or her surroundings.
Asymptomatic cases are the major cause of spread of the virus. More than 50% of reported symptomatic cases have been traced to infected individuals who had no symptoms. The immune response in those individuals had been robust enough to prevent recognizable disease. They could, however, carry the virus for up to two weeks. This tendency is thought to be especially common in younger adults. 
Vaccinated individuals will also have a more robust immune response when exposed to the virus. Clinical trials on more than 60,000 people have proved that there is a 95% reduction in moderate and severe disease cases of COVID-19. However, those trials were not designed to measure asymptomatic cases. 
The results of the two Israeli studies are encouraging. Israeli’s universal health care and advanced data capabilities have provided a nationwide database that can offer insights into how effective the vaccines are outside of controlled clinical trials. To date, more than 30% of Israel’s 9 million population has received both doses of the Pfizer vaccine. By comparison, the United States has fully vaccinated approximately 6% of our population as of Feb. 23.
The first study by Israel’s Sheba Medical Center was published on Feb. 19 in the highly respected Medical journal, The Lancet. The study found that among 7,214 medical staff who received their first dose in January, there was an 85% reduction in symptomatic COVID-19 within 15 to 28 days. There was also a 75% reduction in asymptomatic cases. An important caveat to this study was that the average age of the medical staff was younger than the Israeli population. Not many were over the age of 65.
Findings of the second Israeli study, which also reported fewer asymptomatic cases, were first reported by Reuters on Feb. 19. It has not yet been peer-reviewed.
In addition, Israel’s Health Ministry/Pfizer researchers have found the vaccine to be effective against the British coronavirus variant that makes up about 80 percent of Israel’s confirmed cases.
More research is needed to draw a definitive conclusion, but the studies are among the first to suggest that the Pfizer vaccine may stop the spread of the novel coronavirus and not just prevent people from becoming ill. It is important to remember that vaccine developers have also said more research is needed on transmissibility. In December, Germany’s BioNTech, the co-maker of the Pfizer vaccine, said it would take three to six more months to evaluate the vaccines full effect on transmissibility. 
It is very difficult for us to continue to have patience and perseverance with COVID-19. We are approaching one year since the lockdown began in mid-March. We are waiting for businesses to reopen, education for our children to return to normal, recreational opportunities to improve, social  opportunities to resume, and even our turn to receive the vaccine that will allow all of this to happen. 
I find great hope in the success of the vaccines and the significant decline in the number of cases in our country as more of us follow the guidelines that help to keep all of us safer. I believe if we continue these behaviors and become vaccinated for ourselves and to protect others, we will be able to avoid another surge of COVID-19 cases. This will allow businesses and schools to reopen, we will be able to safely gather with our friends and families, and our travel opportunities will increase. With this progress, our general well-being will improve in the months ahead.


Vaccine update
The opening of the Nordhoff High School vaccine site on Feb. 20 was another significant advance in our opportunity to be vaccinated. More than 400 doses were given on that day. By all accounts, it was extremely well organized with minimal wait times. Transportation for those needing it was coordinated by Help of Ojai. I am so grateful for the efforts of our Ojai Valley Community Hospital, led by Chief Administrative Office Haady Lashkari, the Ojai Unified School District, and Help of Ojai for getting this site open. 
As of Feb. 19, more than 140,000 doses of vaccine have been administered in our county, with nearly 40,000 residents fully vaccinated. A total of 36,000 of those doses have been given to our residents 75 and above, and 25,000 to those age 65 to 74. Weekly vaccines supplies allocated to our county continue to improve and we are able get all of them “into arms” once they have been received. 
For those of you waiting for your opportunity, I encourage you to remember that all of us who want the vaccine will get it. If you are currently eligible, I encourage you to get it now. Many have told me that they were successful in scheduling appointments by going on the county website,, every day (especially Mondays beginning at 7 a.m.) and searching for openings or by calling the county phone number, 805- 477-7161, regularly. It is the goal of this rollout to get everyone vaccinated who wishes to be, and to get it done as soon as vaccine supplies allow.
Stay hopeful, stay persistent, stay properly informed, stay safe and stay well.

— Dr. Jim Halverson is a longtime Ojai physician who writes a weekly column on COVID-19 for the Ojai Valley News. Read about Dr. Halverson writing 47 columns since the first coronavirus case was reported in Ventura County in March 2020 in this week’s OVN special section called “Wellness Ojai 2021.” Also, to read all of Dr. Halverson’s columns, compiled by Phil Caruthers of Ojai, go to the Ojai Valley News website,, and click on the “columns” tab.