If you’re looking for an unbiased, science-based review of the evidence, then you’ve come to the right place. This post covers the current (as of August 2021) evidence available regarding the common question, “Do Vaccines Protect Against the Delta Variant?”, while diving into ways to support your immune system through nutrition. To stay abreast on the current information, always refer to the Center for Disease Control and World Health Organization.
This post was written by Dietetic Intern and Masters candidate, Taylor Stein. All information was reviewed by Elizabeth Shaw, MS RDN CPT. This post is for informational purposes only, not to be misconstrued as medical advice.
Why I’m Writing This Piece as a Registered Dietitian
Truthfully, this post was written out of our own desires to really understand what is going on when it comes to the science right now concerning the delta variant. With so much misinformation out there, Taylor and I decided we’d like to have a one-stop shop with the latest evidence available as of August 2021 when this post was published.
Plus, good health and nutrition are intimately tied with immunity and one’s ability to fight off infections.
Since the pandemic first began, there has been information swirling regarding which supplements or nutraceuticals may be helpful in helping one improve their immune response if infected.
Our hope as two professionals based in science is that we can help provide you the facts and some solid nutrition tips when it comes to incorporating a wide variety of foods in your diet to support your immune system.
COVID-19 Mutations and Variants: WYNTK
During the past 20 months since the pandemic began, there has been concern about how quickly the COVID-19 virus would adapt to its environment.
These mutations occur with the common cold, influenza, and many other communicable viruses. For example, vaccines for the flu are updated on a yearly basis to provide the best protection from severe illness.
While we are still learning about the COVID-19 virus, it has quickly become clear that the vaccines available are effective against all variants in circulation.
More recently, the delta variant has been deemed amongst the media as being the most dangerous. It’s important to note however that being vaccinated still increases the probability of avoiding severe illness, as long as one is vaccinated before being exposed.
Vaccine Effectiveness: What Statistics Show
Firstly, let’s quickly review the stats on vaccine effectiveness (how the vaccine performs in real-world observational studies) across the globe, age groups, general population, and healthcare workers or those living in communal settings 11-14 days after second doses:
- Against SARS-CoV-2 infection, Pfizer-BioNTech & Moderna are 86-99% effective
- Against hospitalizations, Pfizer-BioNTech & Moderna are 94% effective
- Against symptomatic disease, Pfizer-BioNTech & Moderna are 85-90% effective
- Against SARS-CoV-2 infection, Johnson & Johnson/Janssen is 77% effective
Vaccine effectiveness of against asymptomatic infection 7-11 days after second dose:
- 65-92% effective, with lower effectiveness for those who work in healthcare settings
Ultimately, what we can learn from the above information is that the vaccines that have been developed and are available to those over 12 years of age are effective in the real world against infection, hospitalization, and symptomatic disease.
Some vaccines have higher effectiveness than others, however, any vaccine safeguards one better than no vaccine at all!
If one has no contraindications, is eligible to be vaccinated, and does so, as discussed, the chances of catching the virus are very low.
However, breakthrough cases will occur as no vaccine available is 100% effective at ensuring there is no infection (no vaccines have ever been able to achieve 100%).
What we do know is that:
- Evidence indicates that vaccination makes illness less severe and fully vaccinated people are much less likely to be hospitalized or die than people with similar risk factors who are not vaccinated. No unusual patterns of breakthrough cases have been determined yet, i.e., no age, gender, ethnicity, etc. groups are at higher or lower risk.
- If infected, despite vaccination, the virus can still be transmitted to others.
Known Side Effects of the Vaccines
Side effects of the vaccine include pain, redness, and swelling at the injection site, as well as tiredness, headache, muscle pain, chills fever, and/or nausea.
- To reduce injection site symptoms, apply a clean, cool, wet washcloth over the area and utilize your arm to improve circulation. If experiencing fever, drink sufficient fluids and dress lightly to avoid overheating.
- In a study of healthcare workers who had breakthrough cases (39 infected of 1497 workers tested), most had mild symptoms or were asymptomatic although 19% had symptoms that lasted longer than 6 weeks. Most common symptoms included respiratory congestion, muscle pain, and loss of taste or smell. Fewer breakthrough cases experienced fever. For those who experienced “long COVID,” they experienced a prolonged loss of smell, persistent cough, fatigue, weakness, labored breathing, or muscle pain.
- Among those in the study who advised on household transmission, no secondary infections were detected.
What Does Science Say A Vaccinated Person Will Experience If Exposed to Other Variants?
As mentioned previously, the delta variant has been the most contagious of the mutations thus far, and could cause more severe illness than other variants.
However, if one is vaccinated, here is what the research tells us so far:
- Fully vaccinated people who catch the delta variant are at lower risk for severe COVID-19 symptoms which would result in hospitalization and death.
- Most common symptoms are fever, headache, sore throat, and runny nose.
- The delta variant is currently the predominant strain in the US. While studies are ongoing to determine transmission rates among vaccinated people, it has been determined that vaccinated people appear to be infectious for a shorter period of time.
Luckily, it is not news to the scientific community that good nutrition has a significant impact on how well one is able to fight off infection.
Let’s take a deeper dive into the research behind immune health, where nutrition comes into play, and if supplements are really worthwhile.
How Nutrition Plays a Role in COVID and Its Variants
Research is clear that poor nutrition and an unhealthy diet significantly weakens the immune system and increases susceptibility to infectious disease.
A July 2021 study showed diets with a high consumption of saturated fatty acids (SFA), sugars, refined carbohydrates, and low levels of fiber and antioxidants modulate the balance between the adaptive and innate immune responses leading to an impaired host defense against viruses.
With this knowledge, scientists were able to determine which macro- and micronutrients are most important to one’s body under threat of COVID-19 infection.
Firstly, protein, vitamins A, B complex, C, D and E, and trace elements have an important role in the prolonged and effective stimulation of the immune system, as well as repair and regeneration of tissues that have been damaged.
Thus, deficiencies in vitamin and trace element levels could result in a more detrimental fate after being infected.
One can support their immune system by ensuring proper nutrition, keeping the below foods in mind as the best sources of nourishment.
If there are any concerns about if one is doing the very best they can, reach out to a dietitian near you for a helpful hand obviously, but let’s cover some of the basics here first!
What Foods Support Immune Health?
This list is not exhaustive, however is extensive! Use this as a guide to help fuel your immune health!
- Adequate protein from lean animal sources and plant-based sources, particularly arginine (despite being semi-essential i.e., the body can produce adequate amounts normally, however, it may become essential when the body is under stress): turkey, pork loin, chicken, pumpkin seeds, soybeans, peanuts, and spirulina.
- Methionine also plays a role, and can be found in foods like ground turkey, beef, tuna, lean pork, tofu, milk, Brazil nuts, and large white beans.
- Note, these lists are in order from highest contents to significant contents, but less.
- Vitamin A:
- Found in foods like milk, meats, eggs, orange and yellow vegetables.
- B Vitamins:
- Most can be found in enriched or fortified grain products; naturally found forms, if available in plants and animal sources, have higher bioavailability from animal sources.
- Whole wheat flour, rice (rice bran is particularly high), peas, legumes, pork
- Liver, chicken, tuna, turkey breast, salmon
- Meats, whole grain, green leafy vegetables
- Pantothenic acid:
- Beef, poultry, seafood, and organ meats, dairy products, nuts and legumes, mushrooms, avocados, potatoes, and broccoli.
- Egg yolks, cereal grains, human milk, rapeseed oil, royal jelly (also found in low amounts across many foods)
- Milk, fortified cereal, bread, and grain products
- Animal products (meat, poultry, fish, eggs)
- B6 (pryoxidine):
- Animal products, whole grains, vegetables, and nuts
- Vitamin C:
- Found in fruits, particularly citrus fruits and those eaten raw (since C is sensitive to temperature), vegetables (same as fruits), and organ meats.
- Vitamin D:
- Found in the skin and flesh of oily fish (e.g. salmon, mackerel, herring), cod liver oil, and fortified dairy products.
- High dose of vitamin D3 intervention appears not to be useful for moderate to severe COVID-19.
- Vitamin E:
- Found in wheat germ (whole wheat), sunflower oil, safflower oil, olive oil, and canola oil.
- Found in protein rich foods, particularly liver and seafood; also beans and grains (and enriched grains).
- Note that zinc supplements (more than Recommended Daily Intake) might shorten smell recovery, without influencing the complete recovery duration from COVID-19.
- Found in Brazil nuts, seafoods, organ meats and muscle meats, dairy, and whole grains.
- Found in seafood (oysters, crab and lobster), beef liver, rice and pasta, legumes, nuts, and potatoes.
- Found in greens, nuts, seeds, dry beans, whole grains, wheat germ, wheat and oat bran.
Be sure to try these delicious recipes out in your meal plan to help support your immune health!
Where Do Supplements Come Into Play For Immune Health
If any of the above vitamins, minerals, or protein are proving difficult to obtain in adequate amounts, especially while experiencing symptoms of COVID-19 infection that suppress appetite or ability to eat, supplementation with a multivitamin and/or nutrition drinks may be warranted.
For more information about supplements, check out my supplement safety net post!
Now, let’s dive into the potential supplements that have been studied when it comes to COVID-19. Please note this is not our recommendation to try them, but merely sharing what the science has available right now. Always be sure to speak with your own physician before implementing a supplement routine.
SARS-CoV-2 exacerbates gut inflammation and those with COVID-19 have been found to have altered gut microbiomes; it’s been suggested that probiotic supplementation (with beneficial bacteria that have been depleted) can lessen the potential for opportunistic bacteria to multiply. Ultimately, it is proposed, with indirect evidence, that there is potential for probiotic supplementation to help restore gut diversity during or after COVID-19 illness and lessen damage inflicted.
Other dietary supplements:
Lianhua Qinwen, which is made of Forsythia suspensa, Lonicera japonica, Ephedra sinica, Isatis indigotica, Pogostemon cablin, Rheum palmatum, Glycyrrhiza uralensis, Dryopteris crassirhizoma, Rhodiola crenulata, Houttuynia cordata, Prunus sibirica, gypsum and 1-menthol, were found to shorten recovery time and have been deemed safe for consumption when taken as indicated.
Trials are ongoing. It’s safe to consume as directed, but there’s not enough evidence to date that supplementation helps to treat viral respiratory illness.
Trials are ongoing as well; however, studies indicate that increased melatonin levels in the body are correlated with a decrease in catching COVID-19. Also, small studies have shown that melatonin exposure when ill with COVID-19 in hospital correlated with higher survival rates.
While not a supplement, data also suggests you need to get adequate sleep!