Point mutations (n nucleotides) | Similarity probability formula | The probability (expressed as a percent) that two viruses will differ by n or more nucleotides given that they are from the same outbreak. | Average number of viral sequences that would have to be sequenced from the same outbreak to have 1 sequence with n nucleotide changes (1/(a)^{n}) |
---|---|---|---|
1 nucleotide | a^{n} = a^{1} | 17.2% | 6.2 |
2 nucleotides | a^{n} = a^{2} | 2.96% | 38.5 |
3 nucleotides | a^{n} = a^{3} | 0.509% | Approx. 250 |
4 nucleotides | a^{n} = a^{4} | 0.088% | Approx. 1000 |
Any changes | < 20% | > 5 |