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The Moderna Vaccine vs. the Pfizer Vaccine

What we know and don’t know about the differences between the Moderna vaccine and the Pfizer vaccine vs. COVID-19. How good are these shots?
The Moderna Vaccine vs. the Pfizer Vaccine
Close up of doctor hand wearing blue disposable gloves and showing vaccine phial for coronavirus covid-19. Hand holding vial dose vaccine for sars-coV-2 vaccine, prevention and immunization concept.

Last week the headlines were all about the Pfizer mRNA vaccine (BNT162b2) for COVID-19. We were told in the press release that this vaccine was “more than 90% effective in preventing COVID-19.” That got everyone excited. The stock market took off. This week we are told that the Moderna vaccine (mRNA-1273) might be even better. The official press release stated that the vaccine efficacy rate was 94.5%.

Press Releases vs. Data?

Let’s be honest. We hate trying to analyze press-release data. We much prefer published research that has been peer reviewed. Of course, that is not possible when everyone is dying (literally and figuratively) for an effective vaccine. Until we get total access to all the data from all the clinical trials we will have to rely upon the companies to be as transparent as possible.

Last week we wrote about the Pfizer vaccine at this link. We were told that it was more than 90% effective in preventing COVID-19. The company revealed that of the 43,538 enrolled participants there were 94 confirmed cases of COVID-19. What we did not learn was how many of the 94 received vaccine and how many received placebo.

On Monday, November 16, 2020, we learned a bit more about the Moderna vaccine trial. Of the 95 cases of COVID-19 that were reported, 90 had received placebo and 5 got the Moderna vaccine. That is how they reached 94.5% effectiveness. Of the 95 SARS-CoV-2-positive subjects, 11 developed serious cases of COVID. None, however, were in the vaccine group. That’s very good preliminary news.

Vaccine Effectiveness:

From our vantage point there is one amazing similarity between the Pfizer vaccine and the Moderna vaccine. The success rate between the two—90 to 95%—is amazingly similar! That suggests that the new mRNA technology that both utilize is highly effective.

Let’s put this vaccine success rate into perspective. We have been tracking influenza vaccine effectiveness for years. Researchers reviewed the medical literature from 1967 to 2011. Of the thousands of articles that have been published, they narrowed their focus to 31 of the very best analyses. Of the randomized controlled trials, the pooled efficacy was 59% (Lancet Infectious Diseases, online, Oct. 26, 2011). Some years the flu shot was only 16% effective. In the best years it reached 76% efficacy.

We have analyzed data from the CDC between 2004 and 2018. The overall effectiveness of the modern influenza vaccines over those years was 41% with a low of 10% and a high of 60%. Not terribly impressive, in our opinion. If the flu shot were 90 to 95% effective, we would be overjoyed. Let’s hope that long-term evaluation maintains this level of benefit for the COVID-19 vaccines!

Vaccine Similarities and Differences:

Both the Pfizer and the Moderna vaccine have been tested in a diverse patient population. In the Moderna trial of 30,000 volunteers there were more than 3,000 African American participants, 6,000 Hispanic subjects, 7,000 individuals over the age of 65 and 5,000 people with high-risk chronic conditions.

Adverse reactions were never severe enough to stop the trials. The Johnson & Johnson COVID-19 vaccine trial was temporarily halted due to an adverse reaction in one of the participants.

The kinds of side effects that have been reported for the Moderna vaccine include pain at the site of the injections, muscle aches, joint pain, fever, headache and fatigue. People who got the Pfizer shots have complained of headache, fever, fatigue and injection site pain. Neither vaccine trial has been halted. 

The Big Storage Issue:

By now you have no doubt heard about the big difference between the Pfizer vaccine and the Moderna vaccine. It has to do with storage and shipping. To remain viable, the Pfizer vials must be kept at minus 94 degrees F. Shipping at that temperature and then storing the vaccine in pharmacies, hospitals and medical clinics will be challenging. No standard refrigerator can get that low. 

Moderna’s vaccine can be stored at minus 4 degrees F. It can be kept in a standard refrigerator for a month, whereas the Pfizer vaccine can only last for 5 days or so in a fridge (35.6 to 46.4 degrees F). There is also the suggestion that Moderna’s vials can be kept at room temperature for 12 hours while shots are being administered.

Looking down the road, CureVac has an mRNA vaccine called CVnCoV. This German biotech company reports that its vials can be kept up to 24 hours at room temperature and for three months in the refrigerator.

The People’s Pharmacy Perspective on Vaccines:

There is much we do not yet know about COVID-19 vaccines. We wish that there were a more scientific and coordinated way of releasing the data. We dislike the idea that drug companies are driving communication via press releases.

Will the initial effectiveness hold up? Will the benefits last for at least a year or longer? Will the vaccines prevent serious illness and deaths? Will any serious complications show up? Only time will tell. The initial data are promising, though, and we remain optimistic. Vaccines could change the trajectory of the coronavirus pandemic.

We know that many Americans are suspicious about vaccines in general and the COVID-19 vaccine in particular. Some worry that the vaccines have been rushed into production. Well, there is a pandemic killing over a thousand people each day in the U.S. That’s why the program was called Operation Warp Speed. From the experts we have consulted, though, there have been no short cuts on safety.

There is also the political cloud that seems to be hovering over almost everything these days. Some commenters believe that the vaccine developers delayed news of the effectiveness of the shots until after the election. We have yet to see a drug company deliberately delay good news. There are billions of dollars at stake. Pharmaceutical manufacturers often try to delay bad news, not good news. 

We try to stick with the science here at The People’s Pharmacy. As of today, the U.S. has more than 11 million COVID cases and we are close to 250,000 deaths. There are spikes in cases all across the country. Hospitals are reaching capacity and mobile morgue trailers are being ordered in El Paso, Texas, Las Cruces, New Mexico, Marathon County, Wisconsin and Anchorage, Alaska.

It will take coordinated action to get this virus under control over the next few months and the vaccines won’t start to have a significant impact until 2021. Even under the most ideal distribution system, it is unlikely that we will have adequate protection until the spring.

That said, there is a glimmer of light at the end of the tunnel. If people follow the recommendations of public health officials, it is entirely possible that we can begin to get a handle on this third wave, When the vaccines are available, we may be able to put an end to this pandemic. That is our hope.

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About the Author
Joe Graedon is a pharmacologist who has dedicated his career to making drug information understandable to consumers. His best-selling book, The People’s Pharmacy, was published in 1976 and led to a syndicated newspaper column, syndicated public radio show and web site. In 2006, Long Island University awarded him an honorary doctorate as “one of the country's leading drug experts for the consumer.” .
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