Categories
Moderna Pfizer Vaccine

mRNA and DNA

Messenger RNA (mRNA) vaccines (like Pfizer and Moderna) do not alter your DNA.

In fact, they lack all of the basic requirements necessary to alter DNA. In other words, it’s biologically impossible.

In order for a mRNA vaccine to alter someone’s DNA, several events would have to occur…

  1. mRNA would need to enter the cell nucleus, where DNA lives. However, mRNA do not have the “secret door code” (called nuclear access signal) that would allow it to enter. mRNA vaccines can’t get in.
  2. If the mRNA vaccine did get in (which it won’t), mRNA would have to be then converted to DNA. This would require a tool called “reverse transcriptase”, which the vaccine doesn’t have.
  3. Also, if it made it into the nucleus, mRNA would then to need to insert itself into the DNA. The mRNA would need a tool called “integrase” to do this, which the vaccine doesn’t have.

mRNA is found in all living cells. So, sorry to break it to you, but you already have mRNA within you. This is because our cells need instructions on how to function. The mRNA vaccines add a chapter to this instruction manual: “how to properly to fight the COVID19 virus”.

Some vaccines are being developed and tested to target DNA. And they are also safe (but I can explain at another time). Also viruses like HIV can integrate themselves into DNA, but this isn’t true of all viruses, and HIV can only do so with the help of special tools. None, of which, the COVID19 vaccines have.

Love, YLE

Data Sources:
https://www.nature.com/articles/d41586-020-01221-y
https://www.idsociety.org/covid-19-real-time-learning-network/vaccines/vaccines-information–faq/

Categories
Moderna Pfizer Vaccine Variant

Vaccines are made with mutations in mind

The Moderna and Pfizer vaccine induces something called a polyclonal response. Basically, the vaccine instructs the body to generate numerous shaped antibodies that can connect to many different parts of the virus (see picture). Those antibodies are diverse in shape and cover the whole waterfront of the spike protein.

A spike protein mutation here and there would still leave areas for the antibodies to attach. Mutations to those target sites raise the possibility that the vaccines would be less effective, not necessary that they won’t work at all. Mutations are likely a long way from making any vaccine useless. Scientists say it will probably take years.

However, if a random mutation did render a vaccine useless, the mRNA instructions are incredibly easy to change. This is the beauty of this type of vaccine. It’s like editing a Word document; just tweaking the code a little. And, the FDA wouldn’t need Phase I-III trials again. This is because the code isn’t changed enough to concern safety or efficacy. They would just need to see a study with a few dozen people that showed the new code produced satisfactory amounts of antibodies and protection against the mutated virus.

According to GISAID (a public genetic database of the virus) there’s about 12,000 known mutations for the COVID-19 virus. And the mutations in a few (UK, SA, Brazil, and Nigerian variants) look like they change some of the target sites, but certainly not all.

We are still very much hopeful for the effectiveness of the vaccines.

Love, YLE

Some data sources for more reading:
GISAID: https://www.gisaid.org
WHO 12,000: https://www.who.int/publications/m/item/weekly-epidemiological-update—5-january-2021
Mutations: https://www.statnews.com/2021/01/07/coronavirus-mutation-vaccine-strength/
https://elifesciences.org/articles/61312

Categories
Drug treatments Moderna Pfizer

Fighting Misinformation

Lots of misinformation bubbling up lately. Here is the science you can use to dismiss a few of them…

Ivermectin. 

This is an anti-parasitic medication, which MAY have the ability to reduce COVID19 mortality. A recent study, called ICON, pulled medical records from patients in four Florida hospitals: 172 COVID patients treated with Ivermectin and 107 treated without. Scientists found that mortality decreased among patients with Ivermectin. HOWEVER, the patients that got Ivermectin were also more likely to get steroids too, which we know helps fight COVID19. So, we aren’t sure if people were less likely to die because of steroids or because of ivermectin. There has also been one test tube study and two small randomized control trials (Egypt and Iraq). Ivermectin is definitely something to watch, but we certainly don’t have enough evidence to change COVID19 treatment. Don’t start taking your pet’s ivermectin prescription. We need stronger, larger studies.

65+ with comorbidities in vaccine trials. 

Many people have asked (or stated) that vaccine trials didn’t include anyone that was 65+ with comorbidities. I’m not sure where this misinformation budded from because this is 100% incorrect. Not even close to being true. Both Moderna and Pfizer included patients 65+ with comorbidities (see Tables attached) and vaccines worked swimmingly well. In Pfizer, vaccine efficacy was 91.7% among those aged 65+ with a comorbidity. 

Moderna (can be found in the supplement)
Pfizer for all patients (can be found in the supplement)

No asymptomatic spread. 

Anti-lockdown warriors have recently used a JAMA publication to justify no asymptomatic spread. This scientific article was a meta-analysis; an incredibly strong study that pools previous studies (I’ve posted on this type of study before, search my blog for “meta-analysis” for more info). Briefly, the article combined 54 previous studies to assess secondary attack rates (how often an infected person infects others at home). The misinformation budded from a sub-analysis of only 4 studies, which found secondary attack rates was lower among asymptomatic people compared to non-asymptomatic people in households. This is much different than stating that there is no asymptomatic transmission in the community. 

Hope this helps!

Love, YLE

Data Sources…

Ivermectin: ICON study: https://journal.chestnet.org/article/S0012-3692(20)34898-4/fulltext; Iraq study: https://www.medrxiv.org/content/10.1101/2020.10.26.20219345v1; Egypt study: https://www.researchsquare.com/article/rs-100956/v1; In vitro study: https://pubmed.ncbi.nlm.nih.gov/32251768/

65+ with comorbidities:  Moderna Phase III: https://www.nejm.org/doi/full/10.1056/NEJMoa2035389; Pfizer Phase III: https://www.nejm.org/doi/full/10.1056/NEJMoa2034577?query=featured_home

Asymptomatic JAMA article: https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2774102

Categories
AstraZeneca Moderna Pfizer Vaccine

Delayed Second Dose

People who got their first Pfizer and Moderna vaccine are expected to get their second dose 21 and 28 days later. The UK just approved AstraZeneca, of which people got their second dose 28 days later in clinical trials.

However, yesterday the UK made waves by announcing that they are prioritizing first doses. In other words, people won’t get their second dose of AstraZeneca or Pfizer until up to 3 months after their first dose. This is a bold approach… give as many people their first dose as fast as possible (rather than providing two doses to fewer people). Some places in Canada have been doing this and Belgium is considering it too.

Does timing of the second dose matter? This question has sparked quite the scientific debate.

On one hand, this could be a brilliant decision. Especially in a country where transmission is out of control due to a new variant. This decision could result in less deaths. Biologically (and historically) getting a vaccine a day or week late doesn’t matter much. The immune system usually doesn’t need that much precision. And sometimes the longer between doses, the better efficacy. But 3 months later? Not sure.

On the other hand, this could be a regrettable decision. During a pandemic with significant transmission of a disease, getting a vaccine exactly as it had been studied is important because: 1) People are much better off being fully protected. For example, in the Pfizer trial, the level of protection increased dramatically (52% to 95%) after the second dose; 2) The second dose typically provides longer-lasting immunity than the single dose; and, 3) Dr. Paul Bieniasz (Rockefeller biologist that studies the evaluation of viruses) said that this could cause partial antibody resistance among a population that is semi-immunized. “If I were designing a vaccine-resistant [COVID19 virus], I’d do what they are doing in the UK”. This is an experiment in viral evolution during the middle of a pandemic.

So, in short, the vaccine studies weren’t designed for a delayed dose, so we really don’t know the implications. AstraZeneca also hasn’t released their full data report, even though the regulators had a copy this week. So we can’t really parse out the data to make more accurate hypotheses. Word on the street is that some people had their second dose in the AstraZeneca trial much later than 28 days, but I have yet to see that data.

We’ll just have to see how this goes…

Love, YLE