Skip the hot bath after your COVID shot

New research reviews the various adverse effects that can occur following COVID-19 vaccination and highlights several activities to avoid that can exacerbate the reactions.

Serious adverse effects due to the current COVID-19 immunizations occur in only a very small percentage of cases, but clinicians should be astute in determining who may be vulnerable and recognizing them when they occur.

Immunization is vitally important on both a personal and public health level, but significant adverse reactions can occur in a small percentage of cases. Practitioners should be aware of the risks and consider each individual case for vulnerabilities. Research just published in the journal Vaccines entitled What Should We Do after the COVID-19 Vaccination? Vaccine-Associated Diseases and Precautionary Measures against Adverse Reactions summarizes the diseases that can occur resulting from vaccination and specifies four activities to avoid after getting your shot: high-intensity exercise, alcohol, tobacco smoking, and baths. See also the special note for those who have had a COVID-19 infection.

The authors state:

“It is important to be familiar with the differential diagnoses of chest discomfort and organ-specific diseases associated with COVID-19 vaccines as the preparation for booster shots and vaccinations among children aged 5–11 years begins…In this review, we aimed to provide a few recommendations to prevent vaccine-associated disease.”

Types of organ-specific diseases triggered

The authors group adverse reactions to COVID-19 vaccination according system: cardiovascular, respiratory, gastroenterological, renal, neurological, skin, endocrine, collagen, hematologic, and ‘other’ diseases. The full list can be seen in this table.

Mechanisms by which adverse reactions may occur

Inflammatory cytokines

Cytokines refer to small immunoregulatory proteins secreted by cells of the immune system that affect interactions and communications among them.

“One of the most plausible causes of post-vaccine adverse reactions is the increased release of inflammatory cytokines [7,8,9,10]. Inflammatory cytokines, such as IL-6, IL-1β, etc., are released due to the LNP component [lipid nanoparticles] of the mRNA vaccines [9]…The mRNA vaccines increase both immunostimulatory cytokines release and inflammatory cytokines release, especially after the second vaccination and in patients infected by SARS-CoV-2 [10]. The number of deaths after vaccination is higher after the second vaccination (60.6%) than after the first (39.4%) [6]. These similarities may suggest the association in the overproduction of inflammatory cytokines.”

Autoimmunity

Autoimmune conditions can be provoked or exacerbated by excessive IL-6 signalling and especially due to cross-reactivity between viral spike protein and human antigens (molecules that trigger an antibody response). This is a special concern given the dramatic increase in autoimmunity occurring over the last couple of decades.

“Autoimmunity may result from IL-6 overproduction and cross-reactivity. IL-6 inhibits regulatory T cell (Treg) differentiation, promotes inflammatory helper T cell (Th17) differentiation, and, thus, induces autoimmune and inflammatory diseases [113]. Autoimmune and inflammatory diseases, including AIH [11,13], AE [60], RA [11], and SLE [99], have been implicated in post-vaccine responses. Autoimmunity may also result from the cross-reactivity between human tissue antigen and the SARS-CoV-2 spike protein [93]. As COVID-19 mRNA vaccines encode the SARS-CoV-2 spike protein, autoantibodies may be produced due to the cross-reactivity between the SARS-CoV-2 spike protein and thyroid protein. A link between vaccine-induced autoimmunity and the human leukocyte antigen gene has also been suggested [88].

…although reports are limited, vaccines are also known to relapse autoimmune diseases such as MG, GBS, Graves’ disease, and RA [64,66,89,128]. Therefore, autoimmune diseases require careful observation before and after vaccination.”

Eosinophilia

Eosinophilia is an overproduction of eosinophils, a type of white blood cell that fights infections and is involved in inflammatory processes, especially allergic disorders.

“Eosinophilic myocarditis, eosinophilic pneumonia, EGPA (relapse), eosinophilic cellulitis, eosinophilic panniculitis, and non-episodic angioedema with eosinophilia have been reported following COVID-19 vaccination [20,21,22,23,24,25]. SARS-CoV-1 vaccines have also been shown to induce eosinophilia in the lungs of mice [114]. Andrew et al. reported that the SARS-CoV-1/-2 spike protein might cause eosinophilia associated with a Th2 immune response [115].

ACE2 Downregulation

ACE2 is a protein on the surface of cell membranes that functions as an important enzyme to convert angiotensin II (Ang II) to Ang1–7, leading to opening of the blood vessels and heart protection.

“Post-vaccine adverse reactions may also be the result of the downregulation of ACE2 [26,27]…The increase in Ang II and the decrease in Ang1–7 trigger the NF-kB pathway, which further promotes the release of inflammatory cytokines, including IL-6, IL-1β, etc. [116]. Myopericarditis is more common in young men than in women, which may be related to the increased level of ACE2 in the latter due to estrogen [117].”

The four activities to avoid

High-intensity exercise, alcohol, tobacco smoking, and baths all have the potential promote inflammatory cytokines such as IL-6.

Strenuous exercise

“High-intensity exercise increases the expression of the NLRP3 gene and inflammatory cytokines (IL-1β and IL-18) compared to moderate-intensity exercise [29]. Moderate-to-low-intensity training is recommended for athletes instead of high-intensity at the time of vaccination [118]. As a precautionary measure against post-vaccination myocarditis in Singapore, young individuals, including children and adolescents, are advised to avoid strenuous physical activities such as running, weightlifting, competitive sports, or playing ball games for two weeks after receiving a COVID-19 vaccination [33]. High school-aged male students tend to exercise more than adult men [119], and because myocarditis occurs predominantly in male adolescents, exercise restriction is recommended.”

In addition to what the authors report, exercise stimulates muscle production of IL-6 increasing the risk of autoimmunity and inflammatory flare-ups.

Alcohol and smoking

This should include vaping given what is emerging about its potential harms.

“Alcohol intake and tobacco smoking cause an increased release of inflammatory cytokines [30,31], coronary spasms [121], and arrhythmia [122]. Alcohol intake and tobacco smoking have also been identified as predictive factors for lower antibody titers after vaccination [123,124]. Alcohol intake increases atrial fibrillation (AF) [122]. On the contrary, limiting alcohol reduces the incidence of AF [122]. Therefore, avoiding alcohol consumption and tobacco smoking is important for increasing antibody titers and preventing adverse reactions, such as coronary spasms and arrhythmia.”

Don’t sit in a hot bath

A hot bath usually benefits but can increase IL-6 as observed in Japan where hot baths are routine.

“Taking a bath improves sleep quality, vascular functions, and insulin sensitivity. In contrast, sudden deaths have been associated more frequently with bathing [125]. Inflammatory cytokines, especially IL-6, also increase immediately after bathing [32]. The exact relationship between bathing and COVID-19 vaccination is unknown. However, there have been many sudden deaths while bathing after vaccination in Japan (50 cases; 29 females, 58% and 21 males, 42%; median age 80 (IQR 73–86) years) [34,35] (Figure 1). On the contrary, there have been no reported deaths related to bathing after the influenza vaccine in 2019–2020 [126]…The majority of deaths that occurred while bathing were reported within one week (44/50 cases) after COVID-19 vaccination [34,35] (Figure 1). Based on these reported cases, we suggest that, immediately after COVID-19 vaccination and for several days afterwards, individuals should be advised to take showers rather than baths.”

Special note for those who have had a COVID-19 infection

It can take a long time after acute symptoms of infection have resolved for the immune system to wind down to baseline during which time there can be increased risk of over-stimulation by vaccination. I have observed this firsthand.

“For patients with a history of COVID-19 infection, vaccination may further increase both inflammatory and immunostimulatory cytokines, including IL-6, compared to patients who have not had the infection [10]. Therefore, receiving a COVID-19 vaccine shortly after COVID-19 infection is likely to cause more pronounced inflammation [10] and autoimmunity due to IL-6 overproduction [113]. In Japan, vaccination is recommended about three months after COVID-19 infection for the healthy population [129].”

Bottom Line

The key point is to avoid anything that increases inflammatory cytokine release for at least four days after vaccination.

“Deaths after COVID-19 vaccination usually occur within several days. According to the US surveillance data, the most common cause of death after vaccination is cardiovascular events, followed by cerebrovascular events [5]. Similarly, the Japanese data have shown that deaths during baths are the most common for several days after mRNA vaccination [34,35] (Figure 1). The COVID-19 vaccines promote inflammatory cytokine release [7,8,9,10], and the overproduction of inflammatory cytokines and thrombosis has been documented in cardiovascular pathology [45].

High-intensity exercise, alcohol intake, tobacco smoking, and taking a bath also increase inflammatory cytokine release [29,30,31,32], which may promote cardiovascular events after vaccination. Based on the current evidence, we recommend refraining from high-intensity exercise, alcohol intake, tobacco smoking, and baths immediately after COVID-19 vaccination and for several days afterwards for the prevention of severe adverse reactions, including death…Alcohol intake and tobacco smoking interfere with the increase in antibody titers after vaccination…To increase the vaccine’s effectiveness against COVID-19, we recommend refraining from drinking alcohol and smoking immediately after vaccination.

After COVID-19 vaccination, inflammatory cytokines, autoimmune involvement, eosinophilia, and the downregulation of ACE2 have been reported in relation to various symptoms and diseases. We should recognize these adverse effects and recommend the following precautions immediately after vaccination: limit strenuous exercise, alcohol intake, tobacco smoking, and taking baths.”