Covid, Flu and RSV Protection Protocol

A Guide to Preventing COVID-19, Influenza and Respiratory Syncytial Virus (RSV)

While flu and RSV infections were uncommon in 2020 and 2021, a dramatic increase in infections was documented in the fall and early winter of 2022. We have therefore adapted I-PREVENT to include prevention against flu and RSV. It should be noted that the medications in I-PREVENT are inexpensive, safe, and widely available.

This protocol includes a section on how to prevent infection before you’ve been exposed (pre-exposure/long term) as well as how to prevent infection if you have potentially been exposed (post-exposure/acute, short-term).

At the onset of flu-like symptoms please refer to the I-CARE: Early COVID Treatment or I-CARE: RSV and Flu Treatment Protocols.

About this Protocol

Learn about nutritional therapeutics and how they can help with COVID-19.

Read about the safety of vitamins and nutraceuticals in pregnancy.

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How to prevent infection before you’ve been exposed
  • Antiseptic antimicrobial mouthwash: gargle twice daily (do not swallow). Choose mouthwashes containing chlorhexidine, povidone-iodine, cetylpyridinium chloride, or the combination of eucalyptus, menthol, and thymol. If tooth staining occurs, discontinue use of mouthwash and try another product.

  • Vitamin D: dosing varies; optimal target is greater than 50 ng/ml (Table 1) presents a safe and practical treatment schedule for raising serum concentrations in non-urgent situations. The dosing schedule illustrated in Table 2 should be used when recent serum concentration levels are unavailable.

  • Vitamin C: 500 mg twice daily

  • Zinc: 20-50 mg/day
    Commercial zinc supplements are commonly formulated as zinc oxide or salts with acetate, gluconate, and sulfate.

  • Melatonin: 1-6 mg nightly (slow/extended)
    Begin with 1 mg and increase as tolerated to 6 mg at night. Causes drowsiness. Some patients are intolerant to melatonin, having very disturbing and vivid dreams; in these patients, it may be best to start with a 0.3 mg slow-release tablet and increase slowly, as tolerated.

  • Elderberry syrup, supplements or gummies: follow manufacturer’s dosing recommendations
    Take during periods of high transmission of COVID-19, influenza, and RSV. A triple combination containing elderberry, Vitamin C, and zinc may be a convenient approach. Patients with autoimmune disease should take for 2 weeks or less and monitor their symptoms closely.

  • Resveratrol or a Combination Flavonoid supplement: 400-500 mg daily
    The safety of resveratrol, quercetin, and pterostilbene has not been determined in pregnancy and they should therefore be avoided. Due to the possible drug interaction between quercetin and ivermectin, these drugs should not be taken simultaneously (i.e., should be staggered morning and night).

  • Coffee: One to two cups of caffeinated or decaffeinated coffee per day.

  • Ivermectin: In the current situation of abundant natural immunity along with the recent circulation of less severe and more highly transmissible variants, chronic weekly or Twice weekly ivermectin prophylaxis is no longer applicable to most people.

    The following prophylaxis approaches with ivermectin can be considered and applied based on patient preference, comorbid status, immune status, and in discussion with their provider:

    1. Twice weekly ivermectin at 0.2mg/kg; can be considered in those with significant comorbidity and lack of natural immunity or immunosuppressive states or those with long COVID or post-vaccine syndrome who are not already on ivermectin as treatment
    2. Daily ivermectin just prior to and during periods of high possible exposure such as travel, weddings, conferences, etc.
    3. Immediate initiation of daily ivermectin at treatment doses (0.4mg/kg) upon first symptoms of a viral syndrome

Table 1. Guidance on Upfront Loading Dose Regimens to Replenish Vitamin D Stores in the Body

When serum vitamin D levels are available, the doses provided in this table can be used for the longer-term maintenance of serum 25(OH)D concentration above 50 ng/mL (125 nmol/L). The table provides the initial bolus dose, weekly dose, frequency, and the duration of administration of oral vitamin D in non-emergency situations, in a non-obese, 70 kg adult. *

Baseline Vitamin D
Vitamin D dose, 50,000 IU capsules:
Initial and weekly $
(Number of Weeks)
Total Amount Needed to
Correct Vit. D,
Deficiency (IU, in Millions)#
Initial Bolus Dose (IU) Follow-Up: $$
The Number of 50,000 IU Caps/Week
< 10 300,000 x 3 8 to 10 1.5 to 1.8
11-15 200,000 x 2 8 to 10 1.0 to 1.2
16-20 200,000 x 2 6 to 8 0.8 to 1.0
21-30 100,000 x 2 4 to 6 0.5 to 0.7
31-40 100,000 x 2 2 to 4 0.3 to 0.5
41-50 100,000 x 1 2 to 4 0.2 to 0.3

* A suitable daily or weekly maintenance dose to be started after completing the loading-dose schedule. The dose should be adjusted for those who are overweight (higher) or underweight (lower).
** To convert ng/mL to nmol/L, multiply the amount in ng by 2.5; One µg = 40 IU.
$ Mentioned replacement doses can be taken as single, cumulative doses, two to three times a week spread out over a few weeks.
$$ From the day one of week two onwards.
# Estimated total Vitamin D dose needed to replenish the body stores (i.e., the deficit) is provided in the last column.

(Table adapted with permission from S.J. Wimalawansa)

Table 2. Vitamin D Dosing in the Absence of a Baseline Vitamin D Level

Longer-term maintenance schedules of oral vitamin D based on body weight to maintain the levels above 50 ng/mL (125 nmol/L) when the serum 25(OH)D concentrations are unknown.

Bodyweight Category Dose
kg/day (IU)
Dose (IU)
(Daily or Weekly)*
(Age) or Using BMI
(for age > 18)
(kg/Ht. M2)
Average Body

Daily dose
Once a week
(Age 1-5) 5-13 70 350-900 3000-5000
(Age 6-12) 14-40 70 1000-2800 7000-28,000
(Age 13-18) 40-50 70 2800-3500 20,000-25,000
BMI ≤ 19 50-60
(under-weight adult)
60 to 80 3500-5000 25,000-35,000
BMI < 29 70-90
(normal; non-obese)
70 to 90 5000-8000 35,000-50,000
BMI 30-39 90-120
(obese persons)#
90 to 130 8000-15,000 50,000-100,000
BMI ≥ 40$ 140
(morbidly obese)$
140 to 180 18,000-30,000 125,000-200,000

* Example of a daily or once-a-week dose range for adults with specific body types (based on BMI for white Caucasians and body weight for other ethnic groups). Appropriate dose reductions are necessary for children.
# For those with chronic comorbid conditions, such as hypertension, diabetes, asthma, COPD, CKD, depression, and osteoporosis, and to reduce all-cause mortality, higher doses of vitamin D are needed. For them, one can use the doses that are recommended for persons with obesity (BMI, 30–39: the third row).
$ Those with multiple sclerosis, cancer, migraine headaches, and psoriasis, and those routinely taking medications such as anti-epileptic and anti-retroviral agents that significantly increase the catabolism of vitamin D should consider taking age-appropriate doses recommended for those with morbid obesity (BMI ≥ 40; the higher end of the daily doses in the fourth row).

(Table adapted with permission from S.J. Wimalawansa)

How to prevent infection if you have potentially been exposed
  • Naso-Oropharyngeal hygiene (Nasal Spray and Mouthwash): 2-3 times daily
    The combination of nasal antiseptic sprays and oropharyngeal mouthwashes is strongly suggested. Choose a nasal spray with 1% povidone-iodine (for example Immune Mist™, CofixRX™ or Ionovo™) and a mouthwash containing chlorhexidine, povidone-iodine, cetylpyridinium chloride or the combination of eucalyptus, menthol, and thymol (Listerine™). Some mouthwashes may contribute to temporary tooth staining in certain individuals. Discontinue use and try a different product if this problem arises.

  • Elderberry: four times daily as per manufacturer’s directions for 1 week (gummy, supplement, or syrup)

  • Vitamin C: 500-1000 mg four times daily for 1 week

  • Elemental Zinc: 50-90 mg daily for 1 week

  • Melatonin: 2-5 mg at night (slow/extended release)

  • Resveratrol/Combination Flavonoid supplement: 500 mg twice daily
    A flavonoid combination containing resveratrol, quercetin and pterostilbene is recommended.

    Optional with documented exposure to COVID-19 (positive test):

  • Ivermectin: 0.4 mg/kg immediately, then repeat second dose in 24 hours;
  • Hydroxychloroquine (HCQ): 200 mg twice a day for 5 days.

  • Nitazoxanide: 500-600 mg twice daily for 5 days

Table 3. How to calculate ivermectin dose

Note that ivermectin is available in different strengths (e.g., 3, 6 or 12 mg) and administration forms (tablets, capsules, drops, etc.). Note that tablets can be halved for more accurate dosing, while capsules cannot.

How much do I weigh? What dose does the protocol say?
In pounds In kilograms 0.2 mg/kg: 0.3 mg/kg: 0.4 mg/kg: 0.6 mg/kg:
70-90 32-41 6-8 mg 10-12 mg 13-16 mg 19-25 mg
91-110 41-50 8-10 mg 12-15 mg 17-20 mg 25-30 mg
111-130 50-59 10-12 mg 15-18 mg 20-24 mg 30-35 mg
131-150 60-68 12-14 mg 18-20 mg 24-27 mg 36-41 mg
151-170 69-77 14-15 mg 21-23 mg 27-31 mg 41-46 mg
171-190 78-86