Public health organizations release new recommendations as pandemic rages on

The CDC and other public health entities recently issued a host of new Covid-19 guidance, with recommendations covering topics including vaccine indications, quarantining, and other health considerations during the pandemic.

Covid-19 is still raging across the U.S.

As of Feb. 12, the U.S. has seen 27,229,862 Covid-19 cases, 706,574 of which occurred within the last seven days, according to the CDC. And, to date, there have been 473,699 deaths in the U.S. alone. However, cases have been trending downward over the past 30 days, and so far over 69 million vaccine doses have been delivered, nearly 48.5 million have been administered, and nearly 36 million people have received at least one vaccine dose. A total of 12,085,830 have received a full two doses of mRNA vaccine.

Clarifying Vaccine Contraindications

In a recent guidance update, the CDC added that a history of severe allergic reaction to polyethylene glycol (PEG) or polysorbate should be considered a contraindication to vaccination with either the Pfizer or the Moderna vaccine.

PEG and polysorbate are both components of the mRNA Covid vaccines, the CDC explained. Any individual who has experienced a reaction to either ingredient “should not receive mRNA Covid-19 vaccination…at this time unless they have been evaluated by an allergist-immunologist and it is determined that the person can safely receive the vaccine (e.g., under observation, in a setting with advanced medical care available),” the agency wrote.

The CDC noted that providers should try to determine whether reactions reported after vaccination are consistent with immediate allergic reactions versus other types of commonly observed vaccine reactions, “such as a vasovagal reaction or post-vaccination side effects,” which the agency clarified are not contraindications to receiving a second vaccine dose.

In addition, the CDC explained that a history of any immediate allergic reaction to any other vaccine or injectable therapy that is not related to an mRNA Covid-19 vaccine component or polysorbate should be considered a precaution against vaccination, but not a contraindication.

“Persons with a precaution to vaccination should be counseled about the unknown risks of experiencing a severe allergic reaction and balance these risks against the benefits of vaccination,” the CDC explained.

Allergic reactions that are not related to vaccines, injectable therapies, components of mRNA vaccines, or polysorbates are neither contraindications or precautions against vaccination, the CDC added.

Quarantine Not Required for Fully Vaccinated Individuals

In its updated guidance, the CDC also said that people who have been fully vaccinated for Covid-19 are not required to quarantine following exposure to someone with suspected or confirmed Covid-19 infection.

According to the CDC, vaccinated individuals can skip quarantine if they:

  • “Are fully vaccinated (i.e., ≥2 weeks following receipt of the second dose in a 2-dose series, or ≥2 weeks following receipt of one dose of a single-dose vaccine).
  • “Are within 3 months following receipt of the last dose in the series.
  • “Have remained asymptomatic since the current Covid-19 exposure.”

“Although the risk of SARS-CoV-2 transmission from vaccinated persons to others is still uncertain, vaccination has been demonstrated to prevent symptomatic Covid-19; symptomatic and pre-symptomatic transmission is thought to have a greater role in transmission than purely asymptomatic transmission,” the CDC explained. “Additionally, individual and societal benefits of avoiding unnecessary quarantine may outweigh the potential but unknown risk of transmission, and facilitate the direction of public health resources to persons at highest risk for transmitting SARS-CoV-2 to others. This recommendation to waive quarantine for people with vaccine-derived immunity aligns with quarantine recommendations for those with natural immunity, which eases implementation.”

This does not mean that vaccinated individuals can forego precautions all together, the CDC added—those who are fully vaccinated should still follow current guidance designed to reduce spread, such as wearing masks and social distancing, and they should still follow SARS-CoV-2 testing recommendations and obey state, territorial, tribal, and local travel requirements.

And there are exceptions to this recommendation, the CDC added. Since it is still not currently known how long immunity lasts, those who received their last Covid-19 vaccine dose three months ago or more should still quarantine if they are exposed. And, the agency added, “vaccinated inpatients and residents in healthcare settings should continue to quarantine following an exposure to someone with suspected or confirmed Covid-19; outpatients should be cared for using appropriate Transmission-Based Precautions. This exception is due to the unknown vaccine effectiveness in this population, the higher risk of severe disease and death, and challenges with social distancing in healthcare settings.”

Scheduling Mammograms Around Vaccine Shots

The Society of Breast Imaging (SBI) recommended that patients try to reschedule their mammograms around when they receive the Covid-19 vaccine, due to a potential side effect of the Moderna and Pfizer vaccines that causes axillary adenopathies in the armpits, which some women mistook as a sign of breast cancer.

While axillary adenopathy is rare on normal screening mammograms — “reported in 0.02%-0.04% of screening mammograms,” according to SBI — axillary swelling or tenderness is a potential side effect for both currently authorized Covid-19 vaccines, appearing within two-to-four days following the shot and lasting for up to 10 days.

“As national vaccination efforts are underway, women with a recent Covid-19 vaccine may present for diagnostic workup for newly palpable axillary adenopathy or have new axillary adenopathy identified on routine screening mammography or ultrasound,” SBI wrote in a statement addressing the issue.

In order to ensure proper management of women undergoing breast imaging during the pandemic, SBI offered the following guidance:

  • “If possible, and when it does not unduly delay care, consider scheduling screening exams prior to the first dose of a Covid-19 vaccination or 4-6 weeks following the second dose of a Covid-19 vaccination.
  • “Consider obtaining the following information on patient intake forms: Covid-19 vaccination status, timing and side (left versus right arm) of vaccination. To minimize patient anxiety, consider including this introductory statement: Vaccines of all types can result in temporary swelling of the lymph nodes, which may be a sign that the body is making antibodies in response as intended.
  • “Unilateral axillary adenopathy on screening exams warrants a BI-RADS category 0 assessment to allow for further assessment of the ipsilateral breast and documentation of medical history, including Covid-19 vaccination.
  • “Following appropriate diagnostic work up for unilateral axillary adenopathy in women who received a Covid-19 vaccination in the ipsilateral upper extremity within the preceding 4 weeks, consider a short term follow up exam in 4-12 weeks (BI-RADS category 3) following the second vaccine dose.
  • “If axillary adenopathy persists after short term follow up, then consider lymph node sampling to exclude breast and non-breast malignancy.”

Double Masking: the New Normal?

A study published in this week’s Morbidity and Mortality Weekly Report (MMWR) from the CDC found that wearing a cloth mask over a surgical mask offers better protection against Covid-19, as does wearing a tightly fitted mask.

The MMWR report explained that, during January 2021, the CDC conducted a pair of experiments to assess to methods that could improve mask performance against Covid-19: wearing the cloth mask over a surgical mask, or “double masking,” and knotting and tucking the edges of a surgical mask to improve the fit around the users nose and mouth. In the first experiment, CDC evaluated the efficacy of a three-ply surgical mask alone, a three-ply cotton mask along, and the double-masking method for reducing the number of particles emitted by a cough; the second experiment pitted a double mask and a knotted and tucked surgical mask against various mask configurations to assess reduction in aerosol exposure during a period of breathing.

“Results from the first experiment demonstrated that the unknotted medical procedure mask alone blocked 42.0% of the particles from a simulated cough (standard deviation [SD] = 6.70), and the cloth mask alone blocked 44.3% (SD = 14.0),” the CDC explained. “The combination of the cloth mask covering the medical procedure mask (double mask) blocked 92.5% of the cough particles (SD = 1.9).

“In the second experiment, adding a cloth mask over the source headform’s medical procedure mask or knotting and tucking the medical procedure mask reduced the cumulative exposure of the unmasked receiver by 82.2% (SD = 0.16) and 62.9% (SD = 0.08), respectively,” the CDC continued. “When the source was unmasked and the receiver was fitted with the double mask or the knotted and tucked medical procedure mask, the receiver’s cumulative exposure was reduced by 83.0% (SD = 0.15) and 64.5% (SD = 0.03), respectively. When the source and receiver were both fitted with double masks or knotted and tucked masks, the cumulative exposure of the receiver was reduced 96.4% (SD = 0.02) and 95.9% (SD = 0.02), respectively.”

Based on these results, the CDC updated its guidance on improving mask fit to recommend:

  • Choosing a mask with a nose wire to prevent air from leaking out across the top of the mask.
  • Using a mask fitter or brace over a disposable mask or a cloth mask to prevent air from leaking around the edges of the mask.
  • Making sure the mask fits snugly over nose, mouth, and chin: “If the mask has a good fit, you will feel warm air come through the front of the mask and may be able to see the mask material move in and out with each breath.”
  • Add layers of material by using a cloth mask with multiple layers or wearing a disposable mask under a cloth mask.

The CDC advised against using two disposable masks or wearing another mask over a KN95 mask.

John McKenna, Associate Editor, BreakingMED™

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