Covid-19 mRNA Vaccines: A review of the most recent data as well as special considerations for the vaccine in dermatology patients – Lauren Melnick BS, Chloe Silva BS, and Robin Lewallen MD FAAD

The coronavirus pandemic has affected every single person since the first lockdown in March of 2020 and has resulted in death, social disconnection, loss of jobs, increased distress, and much, much more. While many people are experiencing a new phenomenon known as “covid fatigue,” there is a glimmer of hope with the two vaccines currently being distributed under Emergency Use Authorization (EUA).¹ Many are concerned about the rapid rate at which a novel mRNA vaccine has been approved; however, mRNA trials have been around since the 1990s in animal testing and has been in human trials for numerous infections (Zika, Rabies, CMV, Influenza) and cancer treatment (melanoma, solid organ tumors, lymphomas). ²,³,⁴,⁵  We will review the most recent efficacy and safety data as well as discuss the impact of mutations in COVID-19 such as the United Kingdom (UK) and South African variants on vaccine efficacy. Then we will discuss some special medical and cosmetic dermatologic patient populations and what precautions should be considered in vaccinating these groups.
How Effective is the vaccine?
After 2 doses, there is a 95% and 94.5% efficacy rate for the Pfizer vaccine and Moderna vaccines respectively. ⁶, ⁷  That is very impressive; better than the average annual influenza vaccine, and better than the 50% threshold set by the World Health Organization (WHO) for an effective vaccine. To put that into perspective, the annual influenza vaccine has been between 19-60% effective in the last decade. ⁷
Immunity to the SARS-CoV-2 virus begins approximately 12 days after the first dose of the vaccine, and 2 doses are recommended 21 days or 28 days apart for the Pfizer and Moderna vaccine respectively to provide a longer-term immune response.⁷,⁸
Efficacy of Pfizer mRNA vaccine against Covid-19 after the First Dose ⁷

Efficacy of Moderna mRNA vaccine against Covid-19 after the First Dose ⁸

Is the Vaccine Safe?
Vaccine trials take place in stages, starting with trials on animals, and then three trials on humans: Phase 1, Phase 2 and Phase 3. The Pfizer vaccine had over 40,000 participants and the Moderna vaccine had over 30,000 participants in the Phase 3 portions of their trials.⁷,⁸ No safety steps were compromised and we have two-month safety data that confirms minor side effects from the Phase 3 trials. All study participants will be followed for 2 years.
Post-trial surveillance is also being conducted and the United States (US) government has implemented the most intensive and comprehensive safety monitoring in history with V-safe, Vaccine Adverse Event Reporting System (VAERS), Clinical Immunization Safety Data Assessment (CISA) and Vaccine Safety Datalink (VSD) programs.⁹,¹⁰ Currently, over 29.5 million COVID-19 vaccines have been administered in the United States with the current goal of an additional 150 million doses in the next 100 days.
Vaccine recipients had higher rates of local reactions (pain, erythema, swelling) at the injection site and systemic reactions (fever, headache, myalgias, fatigue) than placebo recipients, with more reactions occurring after the second dose and in younger participants (less than 65). Most reactions were mild to moderate and resolved over 1-3 days.⁷,⁸
“COVID Arm” is a new delayed skin reaction to the mRNA vaccine that has been recently reported most commonly occurs 7-10 days after the initial vaccine. The reaction is more common in women between the ages of 30-50. People who have this reaction should still get their second dose of the vaccine. The reaction is annoying, but the virus is deadly; fear of “COVID Arm” is no reason to avoid getting the vaccine or a second dose. In most cases, no treatment is required. If the rash is itchy oral antihistamines (i.e. Claritin or Benadryl) can be beneficial and if it is tender Tylenol can provide symptomatic relief.11 If the rash results in severe itching, pain, or lasts longer than one week seek treatment with your local primary care physician or dermatologist.
Two examples of “COVID Arm” after the Moderna mRNA Vaccine

A risk of acute hypersensitivity is sometimes observed with vaccines and anaphylaxis has been reported in both Pfizer (5.0 cases per million doses) and Moderna (2.8 cases per million doses) vaccines and were more common in female patients with a history of allergic reactions or anaphylaxis.¹² For comparison, the rate of anaphylaxis of the annual influenza vaccine is 1.3 per million doses given.¹³
Injectable Filler and COVID-19 mRNA vaccines:
Recently, an FDA report was released regarding swelling that may occur at the sites of prior dermal filler placement after an mRNA COVID-19 vaccination. Due to this report, there is an emerging concern among dermatologic patients is the possibility of having localized swelling areas of dermal hyaluronic acid filler placement after receiving the COVID-19 mRNA vaccine. The official CDC guidelines state that mRNA COVID-19 vaccines may be administered to persons who have received injectable dermal fillers and having prior filler is not a contraindication to vaccination.¹⁴
The American Society for Dermatologic Surgery (ASDS) also released a statement regarding dermal filler reactions as follows, “Given currently available data, patients already treated with dermal fillers should not be discouraged or precluded from receiving vaccines of any kind. Similarly, patients who have had vaccines should not be precluded from receiving dermal fillers in the future.” The ASDS also noted that swelling at dermal filler sites is not unique to mRNA vaccination. “Evidence suggests these reactions can be immunologically triggered by viral and bacterial illness, vaccinations such as the influenza vaccine, and dental procedures.”¹⁵,¹⁶,¹⁷ Thankfully, these rare adverse events are temporary and can be managed by an experienced board-certified dermatologist with the use of oral medications or injections to dissolve the filler.
Are there groups that should not get the vaccine?
Currently, getting the mRNA COVID-19 Pfizer or Moderna vaccine is contraindicated if you have a history of immediate allergic reaction of any severity to a previous dose of an mRNA COVID-19 vaccine or any of its components (including polyethylene glycol [PEG]) or to polysorbate (due to potential cross-reactive hypersensitivity with the vaccine ingredient PEG). People who have recently had COVID-19 should wait 90 days from the time of diagnosis to get the vaccine unless directed differently by their health care provider. The vaccine was not studied in children, pregnancy, or immunocompromised patients so there is limited data in these patient populations. Despite it not being studied in immunocompromised patients, the vaccine is currently recommended in this patient population. Numerous medical societies including the Center for Disease Control (CDC) and American College of Obstetricians and Gynecologists (ACOG) feel that the vaccine should not be withheld from women who are pregnant or breastfeeding. Pregnant patients should decide along with their physician if they should receive the vaccine based on their individual risk of exposure and community COVID-19 rates. Children under the age of sixteen should not be vaccinated at this time unless specifically directed by their physician until further clinical trials are performed.¹⁸,¹⁹
Treating psoriatic disease and special considerations for the COVID-19 vaccine:
A task force composed of medical professionals representing the fields of dermatology, rheumatology, and epidemiology as well as the National Psoriasis Foundation (NPF) created guidelines regarding the impact of systemic psoriasis treatments during the COVID-19 pandemic. This task force provided guidance to assist patients with psoriatic disease and their physicians in making strategic and thoughtful decisions regarding their treatment regimens. Existing data does not suggest an increased risk of contracting SARS-CoV-2 infection among patients with psoriasis and/or psoriatic arthritis compared to the general population.²⁰ In fact, biologic therapy for psoriasis may be protective against severe manifestations (ICU hospitalization or death) of SARS-CoV-2 infection according to two large international observational studies.²⁰,²¹
The task force encourages patients with psoriasis to receive either of the available mRNA-based COVID-19 vaccines once they become readily available to their communities in their tier. Those taking systemic immunosuppressive medications, such as corticosteroids, methotrexate, or injectable biologics, to treat their psoriasis and/or psoriatic arthritis can be reassured that these treatments are not contraindications to either of the two currently EUA approved mRNA-based COVID-19 vaccines.²⁰  Theoretically, there is the risk of a reduced response to vaccination in patients on immunosuppressive therapy; however, it is not advised to discontinue systemic psoriasis treatments prior to vaccination as that poses a risk of their symptoms flaring or worsening.
Emerging new variants of SARS-CoV-2:
There are new variants of the coronavirus raising concerns regarding vaccine efficacy. There is evidence that two of the more infectious new strains originated from South Africa (SA) and the United Kingdom (UK). The UK variant is estimated to be 50% more transmissible than the current strain. While neither of the new strains has proven to be more deadly yet, the increased transmission rates result in a higher rate of infections, reduced ICU and hospital capacity, and higher rates of healthcare worker burnout. This strain on the healthcare system may ultimately result in increased deaths.²³
Pfizer vaccine effectiveness against variant strains:
The SARS-CoV-2 virus is characterized by spike proteins, which create its infamous crown-like shape. As previously mentioned, the UK variant is about 50% more transmissible than the current strain.²³ This increase in transmissibility is due to several mutations in the spike protein that distinguish the UK and SA strains from the initial SARS-CoV-2 strain. A particular mutation, known as N501Y, improves the UK variant’s ability to bind to human receptors, thereby promoting its ability to enter human cells and replicate. On January 19, 2021, a study found that the Pfizer COVID-19 vaccine is successful in neutralizing the mutated spike protein of the UK variant.²⁴ Subsequently, an additional study was published on January 27, 2021, which demonstrated that the vaccine is slightly less effective in neutralizing the three spike mutations of the SA variant (E484K+N501Y+D614G).²⁵ With that being said, overall this is great news as the Pfizer vaccine did promote the production of antibodies that fight off viruses with the mutations present in UK and SA variants. While the vaccine was slightly less effective against the SA strain, Pfizer and its European partner BioNTech “believe the small differences in viral neutralization observed in these studies are unlikely to lead to a significant reduction in the effectiveness of the vaccine.”²⁶ Further monitoring for infections in vaccinated individuals will be necessary to determine the effectiveness of the Pfizer vaccine to prevent severe disease produced by new virus variants which will ultimately determine if a booster vaccine to these unique strains will be necessary. Thankfully, modifying and adapting the existing mRNA technology to combat new mutations can be done quickly.²³
Final thoughts:

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