Perspectives On COVID-19 Vaccines
Perspectives On The New Vaccines
With several COVID-19 vaccines poised to become available in the coming weeks I thought you might find it helpful if I shared what I know about the vaccines.
• Let me start by saying I do not have access to any information that is not publicly available. However, I can add my perspective to the publicly available information as a biochemist and research scientist.
• I do not plan to recommend whether you take the vaccine or not. That is your decision. What I hope to do is to provide you with accurate information that will help you make that decision. I also plan to identify some of the inaccurate information that I see circulating on the web.
• I also realize that most of you won’t be eligible for vaccination for several months and we may have important new findings by then. If so, I will update my analysis.
Let’s start with what they are and how they work:
The Pfizer and Moderna vaccines are RNA coated with a fatty lipid layer. The lipid layer fuses with cell membranes, which allows the RNA to enter our cells. Once inside our cells the RNA codes for COVID-19 coat protein. This protein is expressed on the cell surface so our immune system can recognize it and form antibodies to it. This is what gives us immunity to COVID-19.
The AstraZeneca vaccine is a DNA virus which enters our cells and codes for the RNA which, in turn, codes for the COVID-19 coat protein.
And, contrary to what you might have heard, these RNA & DNA vaccines are not going to turn you into mutant ninja turtles. They are designed so they cannot be incorporated into our cellular DNA. They remain in our cells for a short period of time, synthesize viral coat proteins, and then are degraded. (I am not just taking the company’s word on this. I know enough about genetic engineering that I can assure you that certain sequences are needed for the DNA or RNA to be incorporated into our genome. If these sequences aren’t there, the RNA or DNA will not be incorporated.)
Now let’s peek under the hood and look at efficacy:
• The Pfizer vaccine enrolled 44,000 volunteers (22,000 received the vaccine and 22,000 received a placebo). In the Pfizer trial 170 people got COVID, 162 in the placebo group and 8 in the vaccine group. That is where the calculation of 95% effectiveness came from.
• The Moderna vaccine enrolled 30,000 volunteers. In this trial 196 people got COVID, 185 in the placebo group and 11 in the vaccine group. This calculates at 94% effectiveness.
• Some skeptics have pointed out that the number of people who got COVID in these trials were too small for the results to be statistically valid. There is some truth to this criticism. The numbers 8 and 11 are small numbers. Once millions of people have received the vaccine, the efficacy rate may not be 95%. But we can be confident these vaccines will be highly effective.
• Other skeptics have pointed out we don’t know how long the immunity will last. That is true, but, at this point, we also don’t know how long your immunity lasts when you have been affected with COVID.
• AstraZeneca hasn’t released their data yet but have said that one of their trials showed 90% efficacy. Two others showed 60-70% efficacy, which is comparable to the flu vaccine.
Now let’s turn to short-term safety:
• Enough people have received the vaccine in the Pfizer and Moderna clinical trials that we can be reasonably confident there are no serious short-term safety issues with those vaccines. The side effects are rare and are the same as for any vaccine – pain and inflammation at the injection site, muscle and joint pain, mild fever & chills, and headaches. Typically, these resolve in 24-48 hours.
• There was one patient who experienced serious side effect in the AstraZeneca trial. (To put this into perspective, this often occurs in large clinical trials. When you have tens of thousands of people enrolled in a clinical study there will some people who experience a serious illness that may or may not have anything to do with the vaccine). This event received widespread publicity. AstraZeneca halted their clinical trial and unblinded their records so they could see if anyone else who received the vaccine experienced similar symptoms. They did not find any other volunteers with similar symptoms, and the patient who did experience symptoms recovered in a week or two. Most experts feel there is no need to be concerned about the safety of the AstraZeneca vaccine, but they will be keeping their eye on this safety issue as it rolls out.
Next, let’s consider long-term safety. We won’t know about long-term safety issues until millions of people have been vaccinated, but we can make predictions based on what we know about the flu vaccine.
• With the flu vaccine about 1 in a million people will develop an autoimmune response shortly after the infection. The most common one is Guillain-Barre syndrome, but other autoimmune diseases can also develop.
• There has been one incidence in recent years where the risk of developing an autoimmune response was more like 1 in 100,000. That is a possible worst-case scenario.
• What most people don’t tell you is that Guillain-Barre syndrome and other autoimmune diseases can also develop following a bout with the flu or other serious infections.
• The best explanation of this is that whenever our immune systems are strongly stimulated, either by a vaccine or the actual illness, there is a very small (1 in a million) chance that our immune system will go rogue and attack our own cells. The probability of this occurring is probably the same whether you get COVID or receive the COVID vaccine.
• There is some evidence, particularly from type-1 diabetes studies, that adequate vitamin D status may reduce the risk of our immune systems going rogue.
Finally, let’s address the one issue nobody is talking about.
• The effectiveness of any vaccine is dependent on the strength of your immune system.
• That means this is not a time to let down our guard. We need to keep our immune systems strong to protect us until the vaccines become available and to receive maximum benefit from the vaccines once they are available.
• This is also a “Catch-22” situation. The same pre-existing conditions (age, obesity, diabetes, heart disease) that make people particularly susceptible to COVID-19 also weakens their immune systems. The vaccine will likely be much less effective for them. That influences our decision on whether our not to get the vaccine (see below).
Now, let’s address the important question. Should you get vaccinated or not.
• If you are young and healthy, you may be saying to yourself, “If I get COVID, my symptoms are likely to be mild. If I get the vaccine, I have a 1 in a million chance of developing an autoimmune disease. I think I’ll pass.” I understand your perspective.
• If you are young but have an underlying condition like obesity, diabetes, asthma and other lung issues, or heart disease the calculation is more complex. If you get COVID, the consequences are more likely to be severe. COVID-19 is not your seasonal flu. It is a highly contagious and deadly disease.
• Finally, let’s address the public health perspective. Why do public health officials say everyone should get vaccinated, even if you are young and healthy? While they seldom acknowledge it, they are not urging you to get vaccinated to protect yourself. They are thinking about your grandmother or your best friend with diabetes. Their immune systems may be weak, so they may receive incomplete protection from the vaccine. The public health concern is that you could become infected and pass the disease on to them, and it might have deadly consequences for them.
• That is what makes the decision so difficult for the young and healthy. If you focus on what is best for you, the argument for vaccination is not compelling. But, if your focus is on protecting others, the argument for vaccination is much stronger. The person you protect may be the one you love the most.
Now you know the facts. The decision is yours.
credit : steve chaney