The revised guidelines of the US Centers for Disease Control (CDC), for mRNA vaccines against SARS-CoV-2, summarize doctors of the Therapeutic Clinic of the Medical School of the National and Kapodistrian University of Athens.
Theodora Psaltopoulou, Ioannis Danasis, Maria Gavriatopoulou and Thanos Dimopoulos (Rector of EKPA) describe what ages can do it, what are the recommended doses, what are the contraindications and what applies to special categories.
Pfizer-BioNTech: ages 16 years and older
Modern: ages 18 years and older
Pfizer-BioNTech (30μg, 0.3ml): interval 3 weeks
Modern (100μg, 0.5ml): interval 1 month
Vaccinated patients should not take the 2nd dose above 4 days earlier than expected.
The second dose should be given as close as possible to the prescribed schedule. If there is a delay in the second dose, then it can be administered up to 6 weeks after the first dose. There are currently limited data on the effectiveness of vaccination beyond this time frame.
Ideally, Each vaccinated person should receive two doses of the same vaccine.
No data are available on the efficacy and safety of co-administered mRNA vaccines against SARS-CoV-2 with other vaccines. A minimum interval is recommended 14 days before and after administration of another SARS-CoV-2 mRNA vaccine.
However, in emergencies where the expected benefit is expected to outweigh the risks, as in the case of a tetanus vaccine after injury, then they should be co-administered even at shorter intervals.
Currently, no additional booster doses are recommended.
Prophylactic administration of antihistamines before vaccination is not recommended to prevent allergic reactions.
Prophylactic administration of antipyretics or painkillers is not recommended to prevent post-vaccination reactions..
Vaccination of individuals with COVID-19 infection or exposure to SARS-CoV-2
‘People with active or cured COVID-19 infection: Patients with symptomatic or asymptomatic COVID-19 infection should be vaccinated against SARS-CoV-2. PCR testing prior to vaccination is not recommended. Patients with active COVID-19 infection should not be vaccinated until they have recovered from the acute phase of the infection.. The same applies to those who have received the first dose but not the second dose of the vaccine. Although there is no recommendation on the minimum interval between infection and vaccination, the risk of re-infection is considered low in the months following COVID-19 infection but may increase over time as immunity declines.. For those who have been vaccinated and have COVID-19, Therapeutic decisions should not be influenced by previous vaccination.
‘People who have been treated with COVID-19 plasma patients: There are currently no data on the efficacy and safety of mRNA vaccines in those receiving monoclonal antibodies or plasma from COVID-19-cured patients.. Given the half-life of these treatments and that re-infection is uncommon within the first 90 days after the initial infection, vaccination is recommended after the end of 90 days.
Vaccination of people with coexisting diseases
Contraindications to vaccination concern an individual with a history of severe allergic rash reactions, while people with co-morbidities can be vaccinated normally. Immunocompromised patients due to underlying diseases (HIV, malignancies, immunodeficiencies) or due to immunosuppressive therapy may have an increased risk of severe COVID-19 infection. SARS-CoV-2 mRNA vaccination is recommended in immunocompromised patients, in patients with autoimmune diseases, history of Guillain-Barre syndrome, Bell paralysis.
Vaccination of special categories
‘People with skin prefixes: The presence of skin prostheses is not a contraindication to vaccination. Side effects are rare but these are transient and can be treated with corticosteroids and close medical supervision..
Pregnant and breastfeeding women: There are limited data on the efficacy and safety of vaccination in pregnant women. However, and since mRNA vaccines do not contain live virus, no particular risks from vaccination are expected for both mother and fetus. The benefits of vaccination are expected to outweigh the risks. Pregnant women can talk to their doctor about deciding on a vaccine based on their risk of COVID-19 infection. (eg health staff), the risk of serious COVID-19 infection (coexisting diseases), expected efficacy and potential risks from the vaccine and available scientific data. The same goes for breastfeeding women, as mRNA vaccines are not considered to pose a risk to the newborn.
Severe allergic reaction (anaphylaxis) after a previous dose of mRNA vaccine
‘Immediate allergic reaction after a previous dose of mRNA vaccine or after contact with a component of the vaccine such as polyethylene glycol.
Immediate allergic reaction to polysorbate.
These individuals should not receive an mRNA vaccine unless assessed by an allergist-immunologist and deemed that they may be vaccinated under medical supervision..
Public health recommendations for those who have been vaccinated
Vaccinated should continue to follow the measures to prevent the spread of SARS-CoV-2 (face mask, distance maintenance 2 meters, avoid congestion, observance of personal hygiene measures) to protect themselves and those around them.
Vaccinated people exposed to a possible or confirmed case of COVID-19 do not need to be quarantined if they meet the following criteria:
1. They are fully vaccinated and at least they have passed 2 weeks after the second vaccine dose or the first dose for single-dose vaccines
2. They have not passed over 3 months after the last dose of the vaccine
3. They remain asymptomatic
People who do not meet and 3 criteria should continue to follow isolation recommendations after exposure to a possible or confirmed COVID-19 case.
Although the risk of transmission of SARS-CoV-2 from vaccinated patients is not known, Vaccination protects against symptomatic COVID-19 infection and symptomatic and pre-symptomatic transmission appear to play a major role in the transmission of SARS-CoV-2 compared to asymptomatic transmission.. The CDC considers that the individual and social benefits of avoiding unnecessary quarantine outweigh the theoretical risk of asymptomatic transmission.
Exceptions to the above rule are patients and tenants of long-term care units, who should follow the quarantine instructions after exposure to a possible or confirmed case.